FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\Sfmbt
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General Information
Symbol
Dmel\Sfmbt
Species
D. melanogaster
Name
Scm-related gene containing four mbt domains
Annotation Symbol
CG16975
Feature Type
FlyBase ID
FBgn0032475
Gene Model Status
Stock Availability
Gene Summary
Scm-related gene containing four mbt domains (Sfmbt) encodes a subunit of the Polycomb Group protein complex Pho repressive complex (PhoRC). This chromatin binding protein recognizes with high selectivity mono- and dimethylated lysine residues in various histone peptides. [Date last reviewed: 2018-11-15] (FlyBase Gene Snapshot)
Also Known As

dSfmbt

Key Links
Genomic Location
Cytogenetic map
Sequence location
Recombination map
2-47
RefSeq locus
NT_033779 REGION:13169649..13176785
Sequence
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
Gene Ontology (GO) Annotations (16 terms)
Molecular Function (8 terms)
Terms Based on Experimental Evidence (6 terms)
CV Term
Evidence
References
inferred from direct assay
inferred from direct assay
inferred from direct assay
inferred from direct assay
inferred from physical interaction with FLYBASE:Scm; FB:FBgn0003334
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN000261772
inferred from biological aspect of ancestor with PANTHER:PTN000261772
inferred from electronic annotation with InterPro:IPR012313
Biological Process (6 terms)
Terms Based on Experimental Evidence (4 terms)
CV Term
Evidence
References
inferred from genetic interaction with FLYBASE:Scm; FB:FBgn0003334
inferred from direct assay
inferred from mutant phenotype
inferred from mutant phenotype
involved_in oogenesis
inferred from mutant phenotype
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
Cellular Component (2 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
located_in nucleus
inferred from direct assay
inferred from physical interaction with FLYBASE:pho; FB:FBgn0002521
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
is_active_in nucleus
inferred from biological aspect of ancestor with PANTHER:PTN000261772
located_in nucleus
inferred from electronic annotation with InterPro:IPR004092, InterPro:IPR012313
Protein Family (UniProt)
-
Summaries
Gene Snapshot
Scm-related gene containing four mbt domains (Sfmbt) encodes a subunit of the Polycomb Group protein complex Pho repressive complex (PhoRC). This chromatin binding protein recognizes with high selectivity mono- and dimethylated lysine residues in various histone peptides. [Date last reviewed: 2018-11-15]
Gene Group (FlyBase)
PHO REPRESSIVE COMPLEX - PHO VARIANT -
In Drosophila, the Pho repressive complex (PhoRC) can bind Polycomb Response Elements (PREs) and recruit Polycomb repressive complexes. (Adapted from FBrf0190547 and FBrf0220020).
PHO REPRESSIVE COMPLEX - PHOL VARIANT -
In Drosophila, the Pho repressive complex (PhoRC) can bind Polycomb Response Elements (PREs) and recruit Polycomb repressive complexes. (Adapted from FBrf0190547 and FBrf0220020).
Protein Function (UniProtKB)
Polycomb group (PcG) protein that binds to the Polycomb response elements (PREs) found in the regulatory regions of many genes. PcG proteins act by forming multiprotein complexes, which are required to maintain the transcriptionally repressive state of homeotic genes throughout development. PcG proteins are not required to initiate repression, but to maintain it during later stages of development. They probably act via the methylation of histones, rendering chromatin heritably changed in its expressibility. Necessary but not sufficient to recruit a functional PcG repressive complex that represses target genes, suggesting that the recruitment of the distinct PRC1 complex is also required to allow a subsequent repression.
(UniProt, Q9VK33)
Summary (Interactive Fly)

PcG protein - Pleiohomeotic interactor that binds mono- and di-methylated H3-K9 and H4-K20 and acts to maintain a Polycomb-repressed chromatin state

Gene Model and Products
Number of Transcripts
4
Number of Unique Polypeptides
3

Please see the JBrowse view of Dmel\Sfmbt 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 Q9VK33)

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 5.46

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0080491
3939
868
FBtr0080492
4777
1220
FBtr0289981
4846
1243
FBtr0333236
4765
1220
Additional Transcript Data and Comments
Reported size (kB)
Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
FBpp0080069
95.9
868
5.51
FBpp0080070
133.7
1220
5.17
FBpp0288419
136.0
1243
5.42
FBpp0305438
133.7
1220
5.17
Polypeptides with Identical Sequences

The group(s) of polypeptides indicated below share identical sequence to each other.

1220 aa isoforms: Sfmbt-PB, Sfmbt-PD
Additional Polypeptide Data and Comments
Reported size (kDa)
Comments
External Data
Subunit Structure (UniProtKB)

Interacts with pho as a component of the pho-repressive complex (PhoRC).

(UniProt, Q9VK33)
Domain

MBT repeats have unique discriminatory binding activity for methylated Lys residues in H3 and H4; the MBT repeats bind mono- and dimethylated H3K9Me1, H3K9Me2, H4K20Me1 and H4K20Me2 but fail to interact with these residues if they are unmodified or trimethylated.

(UniProt, Q9VK33)
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\Sfmbt 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).

-0.51

Transcript Expression
Polypeptide Expression
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Evidence
References
located_in nucleus
inferred from direct assay
inferred from physical interaction with FLYBASE:pho; FB:FBgn0002521
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\Sfmbt in JBrowse
RNA-Seq by Region - Search RNA-Seq expression levels by exon or genomic region
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) 4-6
  • Stages(s) 7-8
  • Stages(s) 9-10
  • Stages(s) 11-12
  • Stages(s) 13-16
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 12 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 17 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of Sfmbt
Transgenic constructs containing regulatory region of Sfmbt
Aberrations (Deficiencies and Duplications) ( 1 )
Inferred from experimentation ( 1 )
Inferred from location ( 7 )
Variants
Variant Molecular Consequences
Alleles Representing Disease-Implicated Variants
Phenotypes
Orthologs
Human Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Homo sapiens (Human) (19)
11 of 14
Yes
Yes
10 of 14
No
Yes
1  
3 of 14
No
No
3 of 14
No
No
3 of 14
No
No
3 of 14
No
No
3 of 14
No
No
1  
3 of 14
No
Yes
3 of 14
No
Yes
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
1 of 14
No
No
0  
1 of 14
No
No
1 of 14
No
Yes
Model Organism Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Rattus norvegicus (Norway rat) (16)
10 of 14
Yes
Yes
10 of 14
Yes
Yes
3 of 14
No
No
3 of 14
No
No
3 of 14
No
No
3 of 14
No
Yes
3 of 14
No
Yes
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Mus musculus (laboratory mouse) (17)
11 of 14
Yes
Yes
10 of 14
No
Yes
3 of 14
No
No
3 of 14
No
No
3 of 14
No
No
3 of 14
No
No
3 of 14
No
No
3 of 14
No
No
3 of 14
No
Yes
3 of 14
No
Yes
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
1 of 14
No
No
Xenopus tropicalis (Western clawed frog) (16)
9 of 13
Yes
Yes
8 of 13
No
Yes
6 of 13
No
Yes
2 of 13
No
No
1 of 13
No
No
1 of 13
No
Yes
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
Yes
1 of 13
No
Yes
Danio rerio (Zebrafish) (19)
10 of 14
Yes
Yes
10 of 14
Yes
Yes
3 of 14
No
No
3 of 14
No
No
3 of 14
No
Yes
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
Yes
1 of 14
No
Yes
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Caenorhabditis elegans (Nematode, roundworm) (4)
7 of 14
Yes
Yes
7 of 14
Yes
Yes
1 of 14
No
Yes
1 of 14
No
No
Anopheles gambiae (African malaria mosquito) (6)
11 of 12
Yes
Yes
Arabidopsis thaliana (thale-cress) (0)
Saccharomyces cerevisiae (Brewer's yeast) (0)
Schizosaccharomyces pombe (Fission yeast) (0)
Escherichia coli (enterobacterium) (0)
Other Organism Orthologs (via OrthoDB)
Data provided directly from OrthoDB:Sfmbt. Refer to their site for version information.
Paralogs
Paralogs (via DIOPT v9.1)
Drosophila melanogaster (Fruit fly) (7)
3 of 13
2 of 13
2 of 13
2 of 13
1 of 13
1 of 13
1 of 13
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.
    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

    Please see the Physical Interaction reports below for full details
    protein-protein
    Physical Interaction
    Assay
    References
    Summary of Genetic Interactions
    Interaction Browsers

    Please look at the allele data for full details of the genetic interactions
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    External Data
    Subunit Structure (UniProtKB)
    Interacts with pho as a component of the pho-repressive complex (PhoRC).
    (UniProt, Q9VK33 )
    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
    Linkouts
    KEGG Pathways - A collection of manually drawn pathway maps representing knowledge of molecular interaction, reaction and relation networks.
    Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
    SignaLink - A signaling pathway resource with multi-layered regulatory networks.
    Class of Gene
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    2L
    Recombination map
    2-47
    Cytogenetic map
    Sequence location
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    34A7-34A8
    Limits computationally determined from genome sequence between P{lacW}l(2)k11328k11328&P{lacW}l(2)k10105k10105 and P{EP}EP850&P{lacW}l(2)k05911k05911
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    Experimentally Determined Recombination Data
    Location
    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (13)
    Genomic Clones (18)
     

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

    cDNA Clones (60)
     

    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)
      RNAi and Array Information
      Linkouts
      DRSC - Results frm RNAi screens
      Antibody Information
      Laboratory Generated Antibodies
      Commercially Available Antibodies
       
      Cell Line Information
      Publicly Available Cell Lines
       
        Other Stable Cell Lines
         
          Other Comments

          The 'PhoRC' (pho-Sfmbt) complex binds PREs via the pho protein and methylated histones in the chromatin flanking the PREs via the Sfmbt protein to maintain a repressed chromatin state.

          Relationship to Other Genes
          Source for database merge of
          Additional comments
          Nomenclature History
          Source for database identify of

          Source for identity of: Sfmbt CG16975

          Nomenclature comments
          Etymology
          Synonyms and Secondary IDs (7)
          Reported As
          Symbol Synonym
          Name Synonyms
          CG16975
          Scm-related gene containing four mbt domains
          Secondary FlyBase IDs
            Datasets (2)
            Study focus (2)
            Experimental Role
            Project
            Project Type
            Title
            • bait_protein
            Genome-wide localization of chromosomal proteins in cell lines by ChIP-chip and ChIP-Seq.
            • bait_protein
            Genome-wide localization of chromosomal proteins in fly tissues by ChIP-chip and ChIP-Seq.
            Study result (0)
            Result
            Result Type
            Title
            External Crossreferences and Linkouts ( 66 )
            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
            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
            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)
            Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution
            KEGG Pathways - A collection of manually drawn pathway maps representing knowledge of molecular interaction, reaction and relation networks.
            MIST (protein-protein) - An integrated Molecular Interaction Database
            Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
            SignaLink - A signaling pathway resource with multi-layered regulatory networks.
            References (114)