FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\Orc2
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General Information
Symbol
Dmel\Orc2
Species
D. melanogaster
Name
Origin recognition complex subunit 2
Annotation Symbol
CG3041
Feature Type
protein_coding_gene
FlyBase ID
FBgn0015270
Gene Model Status
Current
Stock Availability
11 publicly available
Gene Summary
Origin recognition complex subunit 2 (Orc2) encodes a subunit of the origin recognition complex (ORC), which is essential for the initiation of DNA replication in eukaryotic cells. The product of Orc2 can be phosphorylated by CK2 and Cdks in vivo and in vitro. [Date last reviewed: 2019-03-14] (FlyBase Gene Snapshot)
All Summaries
Also Known As

DmORC2, k43, ORC, l(3)K43, l(3)88Ab

Key Links
Genomic Location
Cytogenetic map
88A3-88A3
Sequence location
Recombination map
3-54
RefSeq locus
NT_033777 REGION:13964885..13967075
Sequence
Get Decorated FASTA
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
NCBI
UCSC
Ensembl
PopFly
Function
Gene Ontology (GO) Annotations (14 terms)
Molecular Function (2 terms)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
enables chromatin binding
inferred from direct assay
(Baldinger and Gossen, 2009)
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
enables DNA replication origin binding
inferred from biological aspect of ancestor with PANTHER:PTN000362151
(GO Reference Genome Project, 2011-)
Biological Process (7 terms)
Terms Based on Experimental Evidence (6 terms)
CV Term
Evidence
References
involved_in chromosome condensation
inferred from mutant phenotype
(Christensen and Tye, 2003)
involved_in DNA replication initiation
inferred from mutant phenotype
(Kim and Orr-Weaver, 2011)
inferred from direct assay
(Chesnokov et al., 1999)
involved_in DNA replication
inferred from mutant phenotype
(Christensen and Tye, 2003, Pflumm and Botchan, 2001, Loupart et al., 2000)
involved_in eggshell chorion gene amplification
inferred from mutant phenotype
(Zhang and Tower, 2004)
involved_in mitotic chromosome condensation
inferred from mutant phenotype
(Pflumm and Botchan, 2001)
involved_in mitotic spindle organization
inferred from mutant phenotype
(Pflumm and Botchan, 2001)
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
involved_in DNA replication
inferred from electronic annotation with InterPro:IPR007220
(InterPro Project Members, 2004-)
involved_in DNA-templated DNA replication
inferred from sequence or structural similarity with SGD:S000000264
(Gossen et al., 1995)
Cellular Component (5 terms)
Terms Based on Experimental Evidence (4 terms)
CV Term
Evidence
References
located_in alpha-heterochromatin
inferred from direct assay
(Pak et al., 1997)
located_in heterochromatin
inferred from direct assay
(Pak et al., 1997)
part_of nuclear origin of replication recognition complex
inferred from direct assay
(Chesnokov et al., 1999)
located_in nucleus
inferred from direct assay
(Kopytova et al., 2016)
inferred from direct assay
(Gossen et al., 1995)
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
part_of nuclear origin of replication recognition complex
inferred from biological aspect of ancestor with PANTHER:PTN000362151
(GO Reference Genome Project, 2011-)
inferred from sequence or structural similarity with SGD:S000000264
(Gossen et al., 1995)
located_in nucleus
inferred from electronic annotation with InterPro:IPR007220
(InterPro Project Members, 2004-)
part_of origin recognition complex
inferred from electronic annotation with InterPro:IPR007220
(InterPro Project Members, 2004-)
Gene Group (FlyBase)
Protein Family (UniProt)
Belongs to the ORC2 family. (Q24168)
Protein Signatures (InterPro)
Summaries
Gene Snapshot
Origin recognition complex subunit 2 (Orc2) encodes a subunit of the origin recognition complex (ORC), which is essential for the initiation of DNA replication in eukaryotic cells. The product of Orc2 can be phosphorylated by CK2 and Cdks in vivo and in vitro. [Date last reviewed: 2019-03-14]
Gene Group (FlyBase)
ORIGIN RECOGNITION COMPLEX -
The Origin Recognition Complex (ORC) is a multi-subunit complex that binds replication origin during replication initiation. Many ORC subunits belong to the AAA+ superfamily of ATPases. (Adapted from FBrf0227879).
Protein Function (UniProtKB)
Component of the origin recognition complex (ORC) that binds origins of replication (PubMed:11137005). DNA-binding is ATP-dependent, however specific DNA sequences that define origins of replication have not been identified so far (PubMed:11137005). ORC is required to assemble the pre-replication complex necessary to initiate DNA replication (PubMed:11137005). As part of the ORC complex, might also have a role in mRNA export (Probable).
(UniProt, Q24168)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
fs(3)293-19
Eggs of homozygous females defective in late-deposited outer layers of endochorion; endochorionic material deficient. Late-gene expression as measured by mRNA or protein levels defective; deficiency in the level of chorion-gene amplification in follicle cells.
l(3)88Ab
Homozygous larvae contain rudimentary imaginal discs, but disc primordia do not grow during larval development; testes and ovaries smaller than normal, and cell number in central nervous system reduced. Mutant gonads do not survive metamorphosis when implanted into wild-type larvae. Homozygous cuticular clones appear to develop normally, but abdominal clones reduced in frequency and size compared to control clones. Mutant larvae support growth of implanted wild-type discs. Normal gene product postulated to be required for cell proliferation; survival of somatic epidermal clones attributed to perdurance. Larval ganglia exhibit extremely low mitotic index; chromosomes irregularly condensed and chromosome breakage observed (Gatti and Baker, 1989, Genes Dev. 3: 438-53); salivary chromosomes appear normal.
Homozygous females weakly fertile; produce eggs with grossly defective chorions; thin, missing most appendages and permeable. All chorion proteins reduced in abundance; chorion gene amplification reduced to 10% wild-type level (Snyder, Galanopoulos, and Kafatos, l986, Proc. Nat. Acad. Sci. USA 83: 3341-45). Heterozygotes with lethal alleles more extreme and sterile.
Summary (Interactive Fly)

A subunit of the Origin recognition complex, involved in initiation of DNA replication - necessary at the interphase-to-mitosis transition to recruit cdc2 kinase and disassemble RPA foci.

Gene Model and Products
Number of Transcripts
1
Number of Unique Polypeptides
1

Please see the JBrowse view of Dmel\Orc2 for information on other features

To submit a correction to a gene model please use the Contact FlyBase form

Protein Domains (via Pfam)
Isoform displayed:
Pfam protein domains
InterPro name
classification
start
end
Protein Domains (via SMART)
Isoform displayed:
SMART protein domains
InterPro name
classification
start
end
Structure
Protein 3D structure   (Predicted by AlphaFold)   (AlphaFold entry Q24168)

If you don't see a structure in the viewer, refresh your browser.
Model Confidence:
  • Very high (pLDDT > 90)
  • Confident (90 > pLDDT > 70)
  • Low (70 > pLDDT > 50)
  • Very low (pLDDT < 50)

AlphaFold produces a per-residue confidence score (pLDDT) between 0 and 100. Some regions with low pLDDT may be unstructured in isolation.

Experimentally Determined Structures
Crossreferences
PDB - An information portal to biological macromolecular structures
Comments on Gene Model

Low-frequency RNA-Seq exon junction(s) not annotated.

Gene model reviewed during 5.47

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
Orc2-RA
FBtr0082866
NM_169563
1995
618
Additional Transcript Data and Comments
Reported size (kB)

2.2 (northern blot)

(Chesnokov et al., 1999)

2.5 (northern blot)

(Landis et al., 1997)
Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
Orc2-PA
FBpp0082329
69.0
618
6.26
Q24168
NP_731873
AAF55006
Polypeptides with Identical Sequences

There is only one protein coding transcript and one polypeptide associated with this gene

Additional Polypeptide Data and Comments
Reported size (kDa)

618 (aa); 82 (kD observed)

(Gossen et al., 1995)
Comments
External Data
Subunit Structure (UniProtKB)

ORC is composed of six subunits. Interacts with Mcm10 (PubMed:12808023). Interacts with CG9890 (PubMed:30713769). Interaction between the TREX-2/AMEX complex and the ORC complex is required for ORC localization to mRNPs, and consequently mRNA export (PubMed:27016737).

(UniProt, Q24168)
Crossreferences
InterPro - A database of protein families, domains and functional sites
PDB - An information portal to biological macromolecular structures
Linkouts
Sequences Consistent with the Gene Model
Mapped Features

Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Orc2 using the Feature Mapper tool.

External Data
Crossreferences
Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
Linkouts
Expression Data
Testis-specificity index

The testis specificity index was calculated from modENCODE tissue expression data by Vedelek et al., 2018 to indicate the degree of testis enrichment compared to other tissues. Scores range from -2.52 (underrepresented) to 5.2 (very high testis bias).

0.15

Transcript Expression
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
embryonic stage 1 -- 3
organism

Comment: maternally deposited

(Fisher et al., 2012)
embryonic stage 4 -- 6
organism | faint | ubiquitous
(Fisher et al., 2012)
embryonic stage 7 -- 8
antennal anlage

Comment: reported as procephalic ectoderm anlage

(Fisher et al., 2012)
central brain anlage

Comment: reported as procephalic ectoderm anlage

(Fisher et al., 2012)
dorsal head epidermis anlage

Comment: reported as procephalic ectoderm anlage

(Fisher et al., 2012)
visual anlage

Comment: reported as procephalic ectoderm anlage

(Fisher et al., 2012)
ventral ectoderm
(Fisher et al., 2012)
ventral nerve cord primordium

Comment: reported as ventral nerve cord anlage

(Fisher et al., 2012)
embryonic stage 9 -- 10
antennal primordium

Comment: reported as procephalic ectoderm primordium

(Fisher et al., 2012)
central brain primordium

Comment: reported as procephalic ectoderm primordium

(Fisher et al., 2012)
visual primordium

Comment: reported as procephalic ectoderm primordium

(Fisher et al., 2012)
dorsal head epidermis primordium

Comment: reported as procephalic ectoderm primordium

(Fisher et al., 2012)
lateral head epidermis primordium

Comment: reported as procephalic ectoderm primordium

(Fisher et al., 2012)
ventral head epidermis primordium

Comment: reported as procephalic ectoderm primordium

(Fisher et al., 2012)
inclusive hindgut primordium
(Fisher et al., 2012)
ventral nerve cord primordium
(Fisher et al., 2012)
embryonic stage 11 -- 12
central brain primordium
(Fisher et al., 2012)
hindgut proper primordium
(Fisher et al., 2012)
Malpighian tubule primordium
(Fisher et al., 2012)
ventral nerve cord primordium
(Fisher et al., 2012)
embryonic stage 13 -- 16
embryonic brain
(Fisher et al., 2012)
embryonic central brain neuron
(Fisher et al., 2012)
embryonic central brain surface glial cell
(Fisher et al., 2012)
embryonic Malpighian tubule
(Fisher et al., 2012)
larval nervous system
(Fisher et al., 2012)
lateral cord neuron
(Fisher et al., 2012)
larval lateral VNC surface glial cell
(Fisher et al., 2012)
larval ventral nerve cord
(Fisher et al., 2012)
northern blot
Stage
Tissue/Position (including subcellular localization)
Reference
embryonic stage & larval stage
(Chesnokov et al., 1999)
Additional Descriptive Data

Orc2 transcripts are maternally deposited and are abundant in early embryos. Levels taper off in later embryonic and larval stages.

(Chesnokov et al., 1999)
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
immunolocalization
Stage
Tissue/Position (including subcellular localization)
Reference
oogenesis stage S10B
egg chamber
• nucleus
(Cayirlioglu et al., 2001)
follicle cell
(May et al., 2005)
western blot
Stage
Tissue/Position (including subcellular localization)
Reference
embryonic stage 1 -- 9

Comment: reference states 0-4 hr AEL

(Gossen et al., 1995)
Additional Descriptive Data

Orc2 protein is preferentially localized to heterochromatin on interphase and mitotic chromosomes.

(Pak et al., 1997)

Western blot analysis shows that Orc2 protein is most abundant in 0-4hr embryos.

(Gossen et al., 1995)
Marker for
 
Subcellular Localization
CV Term
Evidence
References
located_in alpha-heterochromatin
inferred from direct assay
(Pak et al., 1997)
located_in heterochromatin
inferred from direct assay
(Pak et al., 1997)
part_of nuclear origin of replication recognition complex
inferred from direct assay
(Chesnokov et al., 1999)
located_in nucleus
inferred from direct assay
(Kopytova et al., 2016)
inferred from direct assay
(Gossen et al., 1995)
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\Orc2 in JBrowse
RNA-Seq by Region - Search RNA-Seq expression levels by exon or genomic region
Bulk Downloads
RNA-Seq RPKM values for all genes
Reference
See Gelbart and Emmert, 2013 for analysis details and data files for all genes.
Developmental Proteome: Life Cycle
Developmental Proteome: Embryogenesis
External Data and Images
Linkouts
BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
DRscDB - A single-cell RNA-seq resource for data mining and data comparison across species
EMBL-EBI Single Cell Expression Atlas - Single cell expression across species
FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
FlyAtlas2 - A Drosophila melanogaster expression atlas with RNA-Seq, miRNA-Seq and sex-specific data
Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
Flygut - An atlas of the Drosophila adult midgut
Images
FlyExpress - Embryonic expression images (BDGP data)
  • Stages(s) 4-6
  • Stages(s) 7-8
  • Stages(s) 9-10
  • Stages(s) 11-12
FlyBase Wiki
Image Based Resources
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 19 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 11 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of Orc2
Transgenic constructs containing regulatory region of Orc2
Aberrations (Deficiencies and Duplications) ( 15 )
Variants
Variant Molecular Consequences
Alleles Representing Disease-Implicated Variants
Phenotypes
For more details about a specific phenotype click on the relevant allele symbol.
Lethality
Allele
lethal
lethal, with Scer\GAL4Act5C.PI
lethal, with Scer\GAL4insc-Mz1407
lethal (with Orc21)
lethal (with Orc2γ4)
lethal | recessive
lethal | recessive | cold sensitive
lethal - all die before end of larval stage | recessive
lethal - all die before end of pupal stage | recessive
viable
viable, with Dcr-2UAS.cDa, Scer\GAL4elav.PLu
viable, with Scer\GAL4pnr-MD237
viable, with Scer\GAL4tin.CΔ4
Sterility
Allele
female sterile
female sterile | recessive
Other Phenotypes
Allele
abnormal cell number | embryonic stage, with Scer\GAL4VP16.nanos.UTR
abnormal mitotic cell cycle
abnormal mitotic cell cycle | recessive | third instar larval stage
abnormal neuroanatomy | larval stage, with Scer\GAL4insc-Mz1407
abnormal size | adult stage, with Scer\GAL4ey.PH
abnormal size | larval stage
decreased cell number | somatic clone
decreased occurrence of cell division
decreased occurrence of cell division | larval stage
decreased occurrence of cell division | recessive | third instar larval stage
some die during larval stage | recessive
some die during pupal stage | recessive
suppressor of variegation, with In(1)wm4h
suppressor of variegation | dominant, with In(1)wm4h
visible, with Scer\GAL4pnr-MD237
visible | adult stage, with Scer\GAL4en.PU
visible | adult stage, with Scer\GAL4ey.PH
visible | adult stage, with Scer\GAL4nub.PK
wild-type
Phenotype manifest in
Allele
cell cycle
chromatin | larval stage
chromosome, centromeric region
egg chorion
eye, with Scer\GAL4ey.PH
follicle cell
follicle cell | somatic clone
ganglion mother cell | larval stage, with Scer\GAL4insc-Mz1407
imaginal disc
imaginal disc | larval stage
larval brain | third instar larval stage
larval neuroblast | larval stage, with Scer\GAL4insc-Mz1407
mitosis & nuclear chromosome
mitosis & nuclear chromosome (with Df(3R)293γ7)
mitosis & nuclear chromosome (with Orc21)
mitosis & nuclear chromosome (with Orc2γ4)
mitotic cell cycle
mitotic metaphase
mitotic metaphase (with Df(3R)293γ7)
mitotic metaphase (with Orc21)
mitotic metaphase (with Orc2γ4)
nuclear chromosome | larval stage
polytene chromosome | larval stage
primordial germ cell | embryonic stage, with Scer\GAL4VP16.nanos.UTR
spindle
trichogen cell, with Scer\GAL4pnr-MD237
wing, with Scer\GAL4Bx-MS1096
wing, with Scer\GAL4nub.PK
wing blade, with Scer\GAL4nub.PK
wing margin bristle, with Scer\GAL4nub.PK
wing posterior compartment, with Scer\GAL4en.PU
wing vein, with Scer\GAL4nub.PK
Orthologs
Downloads
Download All DIOPT Orthologs
Human Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Source
Compara
Domainoid
eggNOG
Hieranoid
Homologene
Inparanoid
OMA
OrthoDB
OrthoFinder
OrthoInspector
orthoMCL
Panther
Phylome
SonicParanoid
Alignment
Complementation?
Transgene?
Homo sapiens (Human) (1)
Hsap\ORC2
13 of 14
Yes
Yes
Model Organism Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Source
Compara
Domainoid
eggNOG
Hieranoid
Homologene
Inparanoid
OMA
OrthoDB
OrthoFinder
OrthoInspector
orthoMCL
Panther
Phylome
SonicParanoid
Alignment
Complementation?
Transgene?
Rattus norvegicus (Norway rat) (1)
Rnor\Orc2
13 of 14
Yes
Yes
Mus musculus (laboratory mouse) (1)
Mmus\Orc2
12 of 14
Yes
Yes
Xenopus tropicalis (Western clawed frog) (2)
Xtro\orc2
10 of 13
Yes
Yes
Xtro\ppp4r1l
1 of 13
No
Yes
Danio rerio (Zebrafish) (1)
Drer\orc2
11 of 14
Yes
Yes
Caenorhabditis elegans (Nematode, roundworm) (1)
Cele\orc-2
10 of 14
Yes
Yes
Anopheles gambiae (African malaria mosquito) (1)
Agam\AgaP_AGAP000474
12 of 12
Yes
Yes
Arabidopsis thaliana (thale-cress) (1)
Atha\ORC2
11 of 13
Yes
Yes
Saccharomyces cerevisiae (Brewer's yeast) (1)
Scer\ORC2
11 of 13
Yes
Yes
Schizosaccharomyces pombe (Fission yeast) (1)
Spom\orc2
10 of 12
Yes
Yes
Escherichia coli (enterobacterium) (0)
Other Organism Orthologs (via OrthoDB)
Data provided directly from OrthoDB:Orc2. Refer to their site for version information.
Paralogs
Downloads
Download All DIOPT Paralogs
Paralogs (via DIOPT v9.1)
Human Disease Associations
FlyBase Human Disease Model Reports
    Disease Ontology (DO) Annotations
    Models Based on Experimental Evidence ( 0 )
    Allele
    Disease
    Evidence
    References
    Potential Models Based on Orthology ( 0 )
    Human Ortholog
    Disease
    Evidence
    References
    Modifiers Based on Experimental Evidence ( 0 )
    Allele
    Disease
    Interaction
    References
    Disease Associations of Human Orthologs (via DIOPT v9.1 and OMIM)
    Note that ortholog calls supported by only 1 or 2 algorithms (DIOPT score < 3) are not shown.
    Homo sapiens (Human)
    Gene name
    Score
    OMIM
    OMIM Phenotype
    DO term
    Complementation?
    Transgene?
    ORC2; origin recognition complex subunit 2
    13 of 14
    601182
        Functional Complementation Data
        Functional complementation data is computed by FlyBase using a combination of the orthology data obtained from DIOPT and OrthoDB and the allele-level genetic interaction data curated from the literature.
        Interactions
        Summary of Physical Interactions
        Interaction Browsers
        View in FlyBase Interactions Browser   View in MIST tool (external link)
        Please see the Physical Interaction reports below for full details
        protein-protein
        Physical Interaction
        Assay
        References
        Orc2 - CG9890
        anti bait coimmunoprecipitation, western blot
        (Fursova et al., 2018)
        Orc2 - Cdc6
        pull down, molecular weight estimation by staining, electron microscopy
        (Schmidt and Bleichert, 2020, Bleichert et al., 2018)
        Orc2 - Dp
        pull down, western blot
        (Bosco et al., 2001)
        Orc2 - E2f1
        pull down, western blot
        (Bosco et al., 2001)
        Orc2 - Elys
        anti bait coimmunoprecipitation, western blot, Identification by mass spectrometry
        (Richards et al., 2022)
        Orc2 - His3
        anti bait coimmunoprecipitation, Identification by mass spectrometry, western blot
        (Richards et al., 2022)
        Orc2 - Mcm10
        two hybrid
        (Apger et al., 2010)
        Orc2 - Myb
        anti bait coimmunoprecipitation, western blot
        (Beall et al., 2002)
        Orc2 - Orc1
        cross-linking study, Identification by mass spectrometry, electron microscopy, anti bait coimmunoprecipitation, western blot, x-ray crystallography, pull down, molecular weight estimation by staining
        (Schmidt and Bleichert, 2020, Bleichert et al., 2018, Bleichert et al., 2015, Bleichert et al., 2013, Beall et al., 2002)
        Orc2 - Orc3
        x-ray crystallography, pull down, molecular weight estimation by staining, anti bait coimmunoprecipitation, western blot, electron microscopy, cross-linking study, Identification by mass spectrometry
        (Schmidt and Bleichert, 2020, Bleichert et al., 2018, Kopytova et al., 2016, Bleichert et al., 2015, Bleichert et al., 2013, Pinto et al., 1999)
        Orc2 - Orc4
        electron microscopy, cross-linking study, Identification by mass spectrometry, pull down, molecular weight estimation by staining, autoradiography, anti bait coimmunoprecipitation, western blot, x-ray crystallography
        (Schmidt and Bleichert, 2020, Bleichert et al., 2018, Kopytova et al., 2016, Bleichert et al., 2015, Bleichert et al., 2013)
        Orc2 - Orc5
        anti tag coimmunoprecipitation, western blot, anti bait coimmunoprecipitation, x-ray crystallography, electron microscopy, molecular sieving
        (Balasov et al., 2020, Schmidt and Bleichert, 2020, Bleichert et al., 2018, Kopytova et al., 2016, Balasov et al., 2015, Bleichert et al., 2015, Bleichert et al., 2013, Baldinger and Gossen, 2009, Pak et al., 1997)
        Orc2 - Orc6
        anti tag coimmunoprecipitation, anti tag western blot, electron microscopy, anti bait coimmunoprecipitation, western blot, x-ray crystallography, pull down, molecular weight estimation by staining, fluorescence polarization spectroscopy, predetermined participant, cross-linking study, Identification by mass spectrometry
        (Balasov et al., 2020, Schmidt and Bleichert, 2020, Bleichert et al., 2018, Kopytova et al., 2016, Balasov et al., 2015, Bleichert et al., 2015, Bleichert et al., 2013, Beall et al., 2002, Pak et al., 1997)
        Orc2 - Rbf
        anti tag coimmunoprecipitation, anti tag western blot, pull down, western blot, fluorescent resonance energy transfer, fluorescence microscopy
        (Ahlander et al., 2008, Bosco et al., 2001)
        Orc2 - Su(var)205
        affinity chromatography technology, western blot, anti bait coimmunoprecipitation, pull down
        (Pak et al., 1997)
        Orc2 - cav
        anti bait coimmunoprecipitation, western blot
        (Shareef et al., 2001)
        Orc2 - e(y)2
        anti bait coimmunoprecipitation, western blot
        (Kopytova et al., 2016)
        Orc2 - xmas
        anti bait coimmunoprecipitation, western blot
        (Kopytova et al., 2016)
        Summary of Genetic Interactions
        Interaction Browsers
        View in FlyBase Interactions Browser   View in MIST tool (external link)
        Please look at the allele data for full details of the genetic interactions
        Starting gene(s)
        Interaction type
        Interacting gene(s)
        Reference
        Orc2
        suppressible
        htt
        (Dietz et al., 2015)
        Orc2
        enhanceable
        PolE2
        (Sahashi et al., 2013)
        Starting gene(s)
        Interaction type
        Interacting gene(s)
        Reference
        DNaseII
        suppressible
        Orc2
        (Tarayrah-Ibraheim et al., 2021)
        E2f2
        suppressible
        Orc2
        (Cayirlioglu et al., 2003)
        PolE2
        enhanceable
        Orc2
        (Sahashi et al., 2013)
        External Data
        Subunit Structure (UniProtKB)
        ORC is composed of six subunits. Interacts with Mcm10 (PubMed:12808023). Interacts with CG9890 (PubMed:30713769). Interaction between the TREX-2/AMEX complex and the ORC complex is required for ORC localization to mRNPs, and consequently mRNA export (PubMed:27016737).
        (UniProt, Q24168 )
        Linkouts
        BioGRID - A database of protein and genetic interactions.
        DroID - A comprehensive database of gene and protein interactions.
        MIST (protein-protein) - An integrated Molecular Interaction Database
        Pathways
        Signaling Pathways (FlyBase)
        Metabolic Pathways
        FlyBase
        External Links
        External Data
        Class of Gene
        Genomic Location and Detailed Mapping Data
        Chromosome (arm)
        3R
        Recombination map
        3-54
        Cytogenetic map
        88A3-88A3
        Sequence location
        FlyBase Computed Cytological Location
        Cytogenetic map
        Evidence for location
        88A3-88A3
        Limits computationally determined from genome sequence between P{PZ}flfl01949 and P{lacW}trxj14A6&P{PZ}trx00347
        Experimentally Determined Cytological Location
        Cytogenetic map
        Notes
        References
        88A3-88A5
        (determined by in situ hybridisation)
        (Chesnokov et al., 1999)
        Experimentally Determined Recombination Data
        Location

        3-54

        (FlyBase, 2016)

        3-51.6

        (Comeron et al., 2012)

        3-51.1

        (Gatti and Baker, 1989, Tearle and Nusslein-Volhard, 1987)
        Left of (cM)
        Right of (cM)
        Notes
        Stocks and Reagents
        Stocks (11)
        Genomic Clones (15)
         

        Please Note FlyBase no longer curates genomic clone accessions so this list may not be complete

        cDNA Clones (6)
         

        Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see JBrowse for alignment of the cDNAs and ESTs to the gene model.

        cDNA clones, fully sequenced
        BDGP DGC clones
        Other clones
          Drosophila Genomics Resource Center cDNA clones

          For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.

          cDNA Clones, End Sequenced (ESTs)
          BDGP DGC clones
          Other clones
          RNAi and Array Information
          Linkouts
          DRSC - Results frm RNAi screens
          Antibody Information
          Laboratory Generated Antibodies
           

          polyclonal

          (Chesnokov et al., 1999, Gossen et al., 1995)
          Commercially Available Antibodies
           
          Cell Line Information
          Publicly Available Cell Lines
           
            Other Stable Cell Lines
             
            Other Comments

            The ATP dependent DNA binding activity of the Orc1/Orc2 protein complex is reduced or inhibited by phosphorylation of Orc2.

            (Remus et al., 2005)

            Mutants arrest in metaphase with abnormally condensed chromosomes that fail to align at the metaphase plate within a poorly assembled mitotic spindle.

            (Pflumm and Botchan, 2001)

            Orc2 functions in chromosome architecture and replication timing.

            (Loupart et al., 2000)

            The abundance of Orc2 is developmentally regulated and is greatest during the early stages of embryogenesis, concomitant with the highest rate of DNA replication. Fractionation of embryo nuclear extracts reveals that Orc2 is found in a tightly associated complex with five additional polypeptides.

            (Gossen et al., 1995)

            Homozygous larvae contain rudimentary imaginal discs, but disc primordia do not grow during larval development; testes and ovaries smaller than normal and cell number in central nervous system reduced. Mutant gonads do not survive metamorphosis when implanted into wild-type larvae. Homozygous cuticular clones appear to develop normally, but abdominal clones reduced in frequency and size compared to control clones. Mutant larvae support growth of implanted wild-type discs. Normal gene product postulated to be required for cell proliferation; survival of somatic epidermal clones attributed to perdurance. Larval ganglia exhibit extremely low mitotic index; chromosomes irregularly condensed and chromosome breakage observed (Gatti and Baker, 1989); salivary chromosomes appear normal.

            Relationship to Other Genes
            Source for database merge of

            Source for merge of: l(3)dsl5 l(3)SG44

            (Shearn, 1995.5.3)
            Additional comments
            Nomenclature History
            Source for database identify of
            Nomenclature comments
            Etymology
            Synonyms and Secondary IDs (27)
            Reported As
            Symbol Synonym
            CG3041
            (National Institute of Genetics Fly Stocks, 2023-, Çiçek et al., 2016, Schertel et al., 2013, Müller et al., 2010, Ni et al., 2010.12.1, Keleman et al., 2009.8.5)
            DmORC 2
            (Shareef et al., 2001)
            DmORC2
            (Bosco et al., 2001, Loupart et al., 2000, Chesnokov et al., 1999, DiAntonio, 1999, Pinto et al., 1999, Cavalli and Paro, 1998, Huang et al., 1998, Pak et al., 1997, Gossen et al., 1996, Gossen et al., 1995)
            DmOrc2
            (Baldinger and Gossen, 2009, Clarey et al., 2006)
            DmOrc2p
            (Remus et al., 2005)
            ORC
            (Eaton et al., 2010.12.17, Bielinsky et al., 2001, Wakimoto, 1998, Huang and Kellum, 1997)
            ORC2
            (Vorobyeva et al., 2025, Vorobyeva et al., 2021, Zykova et al., 2021, Fursova et al., 2020, Meyer-Nava et al., 2020, Seller et al., 2019, Sidorenko et al., 2019, Fursova et al., 2018, Maksimenko et al., 2018, Hua and Orr-Weaver, 2017, Dietz et al., 2015, Comoglio and Paro, 2014, Belyaeva et al., 2012, Sallé et al., 2012, Demakov et al., 2011, Kim and Orr-Weaver, 2011, Kim et al., 2011, Vatolina et al., 2011, Vatolina et al., 2011, Apger et al., 2010, Deal et al., 2010, Lemos et al., 2010, Macalpine et al., 2010, Sun et al., 2008, Sun et al., 2008, Park et al., 2007, Schwaiger, 2006, Badugu et al., 2005, Craig, 2005, Kohzaki and Murakami, 2005, Sun and Deng, 2005, Aggarwal and Calvi, 2004, Manak et al., 2003, Shareef et al., 2003, Li et al., 2002, Loupart and Heck, 2001, Eissenberg and Elgin, 2000, Whittaker et al., 2000, Asano and Wharton, 1999, DePamphilis, 1999, Krause et al., 1999, Pflumm and Botchan, 1999, Anonymous, 1998, Csink and Henikoff, 1998, Wallrath, 1998, Pak, 1995.12.17)
            Orc-2
            (Somma et al., 2008)
            Orc2
            (Vesala et al., 2024, Ding et al., 2022, Ferguson et al., 2021, Balasov et al., 2020, Meltzer et al., 2019, Parker et al., 2019, Khoroshko et al., 2018, Kohzaki et al., 2018, Sureka et al., 2018, Abruzzi et al., 2017, Heseding et al., 2017, Kopytova et al., 2016, Balasov et al., 2015, Bleichert et al., 2015, Dequéant et al., 2015, Hsu et al., 2015, Kwong et al., 2015, Liang et al., 2014, Bleichert et al., 2013, Gurudatta et al., 2013, Schertel et al., 2013, Yang et al., 2013, Antao et al., 2012, Gallone et al., 2011, Neumüller et al., 2011, Eaton et al., 2010.12.17, Maqbool et al., 2010, Müller et al., 2010, Svitin and Chesnokov, 2010, Baldinger and Gossen, 2009, Jiang et al., 2009, Lin et al., 2009, Ahlander et al., 2008, Doheny et al., 2008, Beall et al., 2007, Buszczak et al., 2007, Calvi et al., 2007, May et al., 2005, Wallace and Orr-Weaver, 2005, Cayirlioglu et al., 2003)
            Orc2p
            (Ehrenhofer-Murray et al., 1995)
            dOrc2
            (Sahashi et al., 2013)
            fs(3)293
            (Orr-Weaver, 1991)
            fs(3)293-19
            k43
            (Baldinger and Gossen, 2009, Okudaira et al., 2005, Tower, 2004, Zhang and Tower, 2004, Cryderman et al., 1999, Spradling, 1999, Calvi et al., 1998, Wallrath, 1998, Landis et al., 1997)
            l(3)88Ab
            (Jarman and Collett, 1998, Tearle and Nusslein-Volhard, 1987)
            l(3)A5
            l(3)K43
            (Castellanos et al., 2008, Mortin et al., 1992, Gatti and Baker, 1989)
            l(3)SG44
            l(3)dsl5
            l(3)k43
            (Heck and Krause, 1997, Krause and Heck, 1996, Ripoll et al., 1987)
            orc2
            (Kim et al., 2021, Powell et al., 2015, Park and Asano, 2011, Park and Asano, 2008, Xie and Orr-Weaver, 2008, Hartl et al., 2007, Foglietti et al., 2006, Claycomb and Orr-Weaver, 2005, Hyun et al., 2005, Okudaira et al., 2005, Baldinger and Gossen, 2003, Cenci et al., 2003, Lee and Orr-Weaver, 2003, Loebel et al., 2000, Whittaker et al., 2000, Royzman et al., 1999, Royzman and Orr-Weaver, 1998)
            rDmORC
            (Remus et al., 2004)
            Name Synonyms
            Origin Recognition Complex subunit 2
            (Comoglio and Paro, 2014)
            Origin recognition complex subunit 2
            (Dequéant et al., 2015)
            lethal(3)88Ab
            origin recognition complex
            (Lin et al., 2009)
            origin recognition complex 2
            (Érdi et al., 2012)
            Secondary FlyBase IDs
            • FBgn0001009
            • FBgn0002365
            Datasets (1)
            Study focus (1)
            Experimental Role
            Project
            Project Type
            Title
            • bait_protein
            modENCODE_replication_factor_ChIP
            Genome-wide localization of essential replication factors characterized by ChIP-Seq and ChIP-chip.
            Study result (0)
            Result
            Result Type
            Title
            External Crossreferences and Linkouts ( 50 )
            Sequence Crossreferences
            NCBI Gene - Gene integrates information from a wide range of species. A record may include nomenclature, Reference Sequences (RefSeqs), maps, pathways, variations, phenotypes, and links to genome-, phenotype-, and locus-specific resources worldwide.
            GenBank Nucleotide - A collection of sequences from several sources, including GenBank, RefSeq, TPA, and PDB.
            GenBank Protein - A collection of sequences from several sources, including translations from annotated coding regions in GenBank, RefSeq and TPA, as well as records from SwissProt, PIR, PRF, and PDB.
            RefSeq - A comprehensive, integrated, non-redundant, well-annotated set of reference sequences including genomic, transcript, and protein.
            UniProt/GCRP - The gene-centric reference proteome (GCRP) provides a 1:1 mapping between genes and UniProt accessions in which a single 'canonical' isoform represents the product(s) of each protein-coding gene.
            UniProt/Swiss-Prot - Manually annotated and reviewed records of protein sequence and functional information
            Other crossreferences
            AlphaFold DB - AlphaFold provides open access to protein structure predictions for the human proteome and other key proteins of interest, to accelerate scientific research.
            BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
            DRscDB - A single-cell RNA-seq resource for data mining and data comparison across species
            EMBL-EBI Single Cell Expression Atlas - Single cell expression across species
            FlyAtlas2 - A Drosophila melanogaster expression atlas with RNA-Seq, miRNA-Seq and sex-specific data
            FlyMine - An integrated database for Drosophila genomics
            InterPro - A database of protein families, domains and functional sites
            KEGG Genes - Molecular building blocks of life in the genomic space.
            MARRVEL_MODEL - MARRVEL (model organism gene)
            PDB - An information portal to biological macromolecular structures
            Linkouts
            BioGRID - A database of protein and genetic interactions.
            Drosophila Genomics Resource Center - Drosophila Genomics Resource Center (DGRC) cDNA clones
            DroID - A comprehensive database of gene and protein interactions.
            DRSC - Results frm RNAi screens
            Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
            FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
            FlyCyc Genes - Genes from a BioCyc PGDB for Dmel
            Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
            Flygut - An atlas of the Drosophila adult midgut
            FlyMet - A comprehensive tissue-specific metabolomics resource for Drosophila.
            Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution
            MIST (protein-protein) - An integrated Molecular Interaction Database
            Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
            References (226)