FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\Orc4
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General Information
Symbol
Dmel\Orc4
Species
D. melanogaster
Name
Origin recognition complex subunit 4
Annotation Symbol
CG2917
Feature Type
protein_coding_gene
FlyBase ID
FBgn0023181
Gene Model Status
Current
Stock Availability
9 publicly available
Gene Summary
Origin recognition complex subunit 4 (Orc4) encodes is a subunit of the hetero-hexameric origin recognition complex (ORC). The ORC binds to origins of DNA replication and scaffolds assembly of a pre-replicative complex, which is required for the initiation of DNA replication. At other loci, the ORC is required for heterochromatin formation. [Date last reviewed: 2019-03-14] (FlyBase Gene Snapshot)
All Summaries
Also Known As

ORC, DmORC4

Key Links
Genomic Location
Cytogenetic map
60E1-60E2
Sequence location
Recombination map
2-107
RefSeq locus
NT_033778 REGION:24795740..24797414
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 (13 terms)
Molecular Function (7 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
enables protein binding
inferred from physical interaction with UniProtKB:Q9VTL1
(Kopytova et al., 2016)
enables ribonucleoprotein complex binding
inferred from direct assay
(Kopytova et al., 2016)
Terms Based on Predictions or Assertions (5 terms)
CV Term
Evidence
References
enables ATP binding
inferred from electronic annotation with InterPro:IPR003959
(InterPro Project Members, 2004-)
enables ATP hydrolysis activity
traceable author statement
(Bleichert et al., 2015)
inferred from electronic annotation with InterPro:IPR003959
(InterPro Project Members, 2004-)
enables DNA binding
inferred from electronic annotation with InterPro:IPR016527
(InterPro Project Members, 2004-)
enables DNA replication origin binding
inferred from biological aspect of ancestor with PANTHER:PTN000250139
(GO Reference Genome Project, 2011-)
enables protein-macromolecule adaptor activity
inferred from biological aspect of ancestor with PANTHER:PTN000250139
(GO Reference Genome Project, 2011-)
Biological Process (2 terms)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
involved_in DNA replication initiation
inferred from direct assay
(Chesnokov et al., 1999)
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
involved_in DNA replication initiation
inferred from biological aspect of ancestor with PANTHER:PTN000250139
(GO Reference Genome Project, 2011-)
involved_in DNA replication
inferred from electronic annotation with InterPro:IPR016527
(InterPro Project Members, 2004-)
Cellular Component (4 terms)
Terms Based on Experimental Evidence (3 terms)
CV Term
Evidence
References
part_of nuclear origin of replication recognition complex
inferred from direct assay
(Chesnokov et al., 1999)
part_of nuclear pore
inferred from direct assay
(Kopytova et al., 2016)
located_in nucleus
inferred from direct assay
(Kopytova et al., 2016)
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:PTN000250139
(GO Reference Genome Project, 2011-)
located_in nucleus
inferred from electronic annotation with InterPro:IPR016527
(InterPro Project Members, 2004-)
part_of origin recognition complex
inferred from electronic annotation with InterPro:IPR016527
(InterPro Project Members, 2004-)
Gene Group (FlyBase)
Protein Family (UniProt)
-
Protein Signatures (InterPro)
Catalytic Activity (EC/Rhea)
ATP hydrolysis activity
RHEA 13065:
Summaries
Gene Snapshot
Origin recognition complex subunit 4 (Orc4) encodes is a subunit of the hetero-hexameric origin recognition complex (ORC). The ORC binds to origins of DNA replication and scaffolds assembly of a pre-replicative complex, which is required for the initiation of DNA replication. At other loci, the ORC is required for heterochromatin formation. [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).
UNCLASSIFIED ATPASES -
This group comprises ATPases that do not classify under other groups in FlyBase.
Gene Model and Products
Number of Transcripts
1
Number of Unique Polypeptides
1

Please see the JBrowse view of Dmel\Orc4 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 Q9W102)

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

Gene model reviewed during 5.52

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
Orc4-RA
FBtr0072425
NM_057972
1615
459
Additional Transcript Data and Comments
Reported size (kB)

2.3, 1.5 (northern blot)

(Chesnokov et al., 1999)
Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
Orc4-PA
FBpp0072330
51.9
459
8.33
Q9W102
NP_477320
AAF47276
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)

458 (aa); 42 (kD observed)

(Chesnokov et al., 1999)
Comments
External Data
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\Orc4 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).

2.89

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 9 -- 10
central brain primordium
(Fisher et al., 2012)
ventral nerve cord primordium
(Fisher et al., 2012)
embryonic stage 11 -- 12
central brain primordium
(Fisher et al., 2012)
embryonic central brain neuron
(Fisher et al., 2012)
embryonic lateral cord
(Fisher et al., 2012)
ventral nerve cord primordium
(Fisher et al., 2012)
embryonic stage 13 -- 16
embryonic brain
(Fisher et al., 2012)
larval nervous system
(Fisher et al., 2012)
lateral cord neuron
(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

1.5kb Orc4 transcripts are maternally deposited and are abundant in early embryos. Levels taper off in later embryonic and larval stages.

(Chesnokov et al., 1999)

2.3 Orc4 transcripts are observed in embryos and larvae with the highest levels in 6-8hr and 8-12hr embryos.

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

JBrowse - Visual display of RNA-Seq signals

View Dmel\Orc4 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) 1-3
  • Stages(s) 9-10
  • Stages(s) 11-12
  • Stages(s) 13-16
FlyBase Wiki
Image Based Resources
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 5 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 8 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of Orc4
Transgenic constructs containing regulatory region of Orc4
Aberrations (Deficiencies and Duplications) ( 3 )
Inferred from experimentation ( 3 )
Gene disrupted in
Df(2R)196
(Park et al., 2002)
Df(2R)BSC856
(McDaniel et al., 2020)
Gene partially disrupted in
Df(2R)ETHattP
(Rao and Deng, 2019.10.23)
Inferred from location ( 8 )
Variants
Variant Molecular Consequences
Alleles Representing Disease-Implicated Variants
Phenotypes
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) (2)
Hsap\ORC4
13 of 14
Yes
Yes
Hsap\CDC6
1 of 14
No
No
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) (2)
Rnor\Orc4
13 of 14
Yes
Yes
Rnor\Cdc6
1 of 14
No
No
Mus musculus (laboratory mouse) (2)
Mmus\Orc4
12 of 14
Yes
Yes
Mmus\Cdc6
1 of 14
No
No
Xenopus tropicalis (Western clawed frog) (2)
Xtro\orc4
8 of 13
Yes
Yes
Xtro\orc1
1 of 13
No
No
Danio rerio (Zebrafish) (2)
Drer\orc4
13 of 14
Yes
Yes
Drer\cdc6
1 of 14
No
No
Caenorhabditis elegans (Nematode, roundworm) (2)
Cele\orc-1
1 of 14
Yes
No
Cele\orc-4
1 of 14
Yes
Yes
Anopheles gambiae (African malaria mosquito) (3)
Agam\AgaP_AGAP007063
11 of 12
Yes
Yes
Agam\AgaP_AGAP004957
1 of 12
No
No
Agam\AgaP_AGAP005176
1 of 12
No
No
Arabidopsis thaliana (thale-cress) (2)
Atha\ORC4
12 of 13
Yes
Yes
Atha\ORC1A
1 of 13
No
No
Saccharomyces cerevisiae (Brewer's yeast) (2)
Scer\ORC4
10 of 13
Yes
Yes
Scer\ORC1
1 of 13
No
No
Schizosaccharomyces pombe (Fission yeast) (3)
Spom\orc4
9 of 12
Yes
Yes
Spom\cdc18
1 of 12
No
No
Spom\orc1
1 of 12
No
No
Escherichia coli (enterobacterium) (0)
Other Organism Orthologs (via OrthoDB)
Data provided directly from OrthoDB:Orc4. Refer to their site for version information.
Paralogs
Downloads
Download All DIOPT Paralogs
Paralogs (via DIOPT v9.1)
Gene Symbol
Score
Source
Compara
Domainoid
eggNOG
Homologene
Inparanoid
OMA
OrthoDB
OrthoFinder
OrthoInspector
orthoMCL
Panther
Phylome
SonicParanoid
Alignment
Drosophila melanogaster (Fruit fly) (2)
Cdc6
1 of 13
Orc1
1 of 13
Human Disease Associations
FlyBase Human Disease Model Reports
Disease Ontology (DO) Annotations
Models Based on Experimental Evidence ( 1 )
Allele
Disease
Evidence
References
Orc4Y162C
model of  Meier-Gorlin syndrome 2
CEA
(McDaniel et al., 2020)
Potential Models Based on Orthology ( 1 )
Human Ortholog
Disease
Evidence
References
ORC4; origin recognition complex subunit 4
model of  Meier-Gorlin syndrome 2
IEA
(FlyBase, 2019-)
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?
ORC4; origin recognition complex subunit 4
13 of 14
603056
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
Orc4 - Cdc6
pull down, molecular weight estimation by staining, electron microscopy
(Schmidt and Bleichert, 2020, Bleichert et al., 2018)
Orc4 - Orc1
electron microscopy, x-ray crystallography, pull down, autoradiography, molecular weight estimation by staining, cross-linking study, Identification by mass spectrometry
(Schmidt and Bleichert, 2020, Bleichert et al., 2018, Bleichert et al., 2015, Bleichert et al., 2013)
Orc4 - Orc2
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)
Orc4 - Orc3
pull down, autoradiography, molecular weight estimation by staining, x-ray crystallography, anti bait coimmunoprecipitation, western blot, electron microscopy
(Schmidt and Bleichert, 2020, Bleichert et al., 2018, Kopytova et al., 2016, Bleichert et al., 2015, Bleichert et al., 2013)
Orc4 - Orc5
x-ray crystallography, anti bait coimmunoprecipitation, western blot, cross-linking study, Identification by mass spectrometry, electron microscopy, pull down, molecular weight estimation by staining, autoradiography
(Schmidt and Bleichert, 2020, Bleichert et al., 2018, Kopytova et al., 2016, Bleichert et al., 2015, Bleichert et al., 2013)
Orc4 - Orc6
pull down, molecular weight estimation by staining, fluorescence polarization spectroscopy, predetermined participant, electron microscopy, cross-linking study, Identification by mass spectrometry, autoradiography, x-ray crystallography, anti bait coimmunoprecipitation, western blot
(Schmidt and Bleichert, 2020, Bleichert et al., 2018, Kopytova et al., 2016, Bleichert et al., 2015, Bleichert et al., 2013)
Orc4 - PCID2
anti tag coimmunoprecipitation, anti tag western blot
(Kopytova et al., 2016)
Orc4 - Su(var)205
pull down, autoradiography
(Pak et al., 1997)
Orc4 - e(y)2
two hybrid, anti bait coimmunoprecipitation, western blot, peptide massfingerprinting
(Maksimenko et al., 2018, Kopytova et al., 2016)
Orc4 - xmas
anti tag coimmunoprecipitation, anti tag western blot, anti bait coimmunoprecipitation, western blot
(Kopytova et al., 2016)
Summary of Genetic Interactions
Interaction Browsers
Starting gene(s)
Interaction type
Interacting gene(s)
Reference
Starting gene(s)
Interaction type
Interacting gene(s)
Reference
External Data
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)
2R
Recombination map
2-107
Cytogenetic map
60E1-60E2
Sequence location
FlyBase Computed Cytological Location
Cytogenetic map
Evidence for location
60E1-60E2
Limits computationally determined from genome sequence between P{EP}Reg-5EP1065 and P{EP}CG9047EP560&P{EP}CG3760EP936
Experimentally Determined Cytological Location
Cytogenetic map
Notes
References
60E1-60E2
(determined by in situ hybridisation)
(Chesnokov et al., 1999)
Experimentally Determined Recombination Data
Location

2-107

(FlyBase, 2016)

2-111.4

(Comeron et al., 2012)
Left of (cM)
Right of (cM)
Notes
Stocks and Reagents
Stocks (9)
Genomic Clones (13)
 

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

cDNA Clones (15)
 

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

(Kopytova et al., 2016, Chesnokov et al., 1999)
Commercially Available Antibodies
 
Cell Line Information
Publicly Available Cell Lines
 
    Other Stable Cell Lines
     
      Other Comments
      Relationship to Other Genes
      Source for database merge of
      Additional comments
      Nomenclature History
      Source for database identify of

      Source for identity of: Orc4 CG2917

      (Zhong, 1999.11)
      Nomenclature comments
      Etymology
      Synonyms and Secondary IDs (9)
      Datasets (0)
      Study focus (0)
      Experimental Role
      Project
      Project Type
      Title
      Study result (0)
      Result
      Result Type
      Title
      External Crossreferences and Linkouts ( 53 )
      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/TrEMBL - Automatically annotated and unreviewed 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.
      iBeetle-Base - RNAi phenotypes in the red flour beetle (Tribolium castaneum)
      MIST (protein-protein) - An integrated Molecular Interaction Database
      Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
      References (76)