FB2024_03 , released June 25, 2024
Gene: Dmel\Blm
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General Information
Symbol
Dmel\Blm
Species
D. melanogaster
Name
Bloom syndrome helicase
Annotation Symbol
CG6920
Feature Type
FlyBase ID
FBgn0002906
Gene Model Status
Stock Availability
Enzyme Name (EC)
DNA 3'-5' helicase (5.6.2.4)
Gene Summary
Bloom syndrome helicase (Blm) encodes a protein that plays important roles in repairing replication fork damage and double-strand breaks. It promotes repair through non-crossover mechanisms, though it also has roles in meiotic recombination. [Date last reviewed: 2019-03-07] (FlyBase Gene Snapshot)
Also Known As

mus309, DmBlm, Ku70, Bloom syndrome helicase ortholog, Bloom helicase

Key Links
Genomic Location
Cytogenetic map
Sequence location
Recombination map
3-51
RefSeq locus
NT_033777 REGION:11736810..11741783
Sequence
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
Gene Ontology (GO) Annotations (27 terms)
Molecular Function (8 terms)
Terms Based on Experimental Evidence (3 terms)
CV Term
Evidence
References
inferred from direct assay
inferred from direct assay
inferred from direct assay
Terms Based on Predictions or Assertions (6 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN000344873
inferred from electronic annotation with InterPro:IPR018982
enables ATP binding
inferred from electronic annotation with InterPro:IPR011545
inferred from sequence or structural similarity with HGNC:1058
inferred from electronic annotation with InterPro:IPR002121
inferred from electronic annotation with InterPro:IPR002121, InterPro:IPR011545
inferred from electronic annotation with InterPro:IPR010997
Biological Process (15 terms)
Terms Based on Experimental Evidence (12 terms)
CV Term
Evidence
References
inferred from mutant phenotype
inferred from genetic interaction with SGD:S000004802
inferred from direct assay
involved_in DNA repair
inferred from genetic interaction with FLYBASE:Gen; FB:FBgn0263831
inferred from mutant phenotype
inferred from direct assay
inferred from mutant phenotype
inferred from genetic interaction with FLYBASE:Irbp; FB:FBgn0011774
inferred from genetic interaction with FLYBASE:Ku80; FB:FBgn0041627
inferred from mutant phenotype
Terms Based on Predictions or Assertions (5 terms)
CV Term
Evidence
References
involved_in DNA recombination
inferred from electronic annotation with InterPro:IPR004589
involved_in DNA repair
inferred from electronic annotation with InterPro:IPR018982
involved_in DNA replication
inferred from electronic annotation with InterPro:IPR018982
Cellular Component (4 terms)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
located_in nucleus
inferred from direct assay
Terms Based on Predictions or Assertions (4 terms)
CV Term
Evidence
References
is_active_in chromosome
inferred from biological aspect of ancestor with PANTHER:PTN000344873
is_active_in cytoplasm
inferred from biological aspect of ancestor with PANTHER:PTN000344873
is_active_in nucleus
inferred from biological aspect of ancestor with PANTHER:PTN001415789
inferred from sequence or structural similarity with UniProtKB:P35187
Gene Group (FlyBase)
Protein Family (UniProt)
Belongs to the helicase family. RecQ subfamily. (Q9VGI8)
Catalytic Activity (EC/Rhea)
3'-5' DNA helicase activity
Couples ATP hydrolysis with the unwinding of duplex DNA by translocating in the 3'-5' direction (5.6.2.4)
Summaries
Gene Snapshot
Bloom syndrome helicase (Blm) encodes a protein that plays important roles in repairing replication fork damage and double-strand breaks. It promotes repair through non-crossover mechanisms, though it also has roles in meiotic recombination. [Date last reviewed: 2019-03-07]
Gene Group (FlyBase)
RECQ-LIKE DNA HELICASES -
The eukaryotic homologues of the Escherichia coli RecQ DNA helicase play conserved roles in the maintenance of genome stability, functioning during DNA replication and possibly in an S phase replication checkpoint. At least three of the human RecQ-like helicases are implicated in heritable diseases: BLM is mutated in Bloom's syndrome, WRN in Werner's syndrome, and RECQL4 in Rothmund-Thomson syndrome. (Adapted from PMID:10893179.)
Protein Function (UniProtKB)
Participates in DNA replication and repair (By similarity). Exhibits a magnesium-dependent ATP-dependent DNA-helicase activity that unwinds single- and double-stranded DNA in a 3'-5' direction (By similarity). Involved in DNA double strand break repair, including the synthesis-dependent strand annealing (SDSA) pathway (PubMed:25205745). Involved in DNA interstrand cross-link repair (PubMed:25205745).
(UniProt, Q9VGI8)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
mus309 (J.B. Boyd)
Larval survival hypersensitive to exposure to methyl methanesulfonate and nitrogen mustard.
Summary (Interactive Fly)

RecQ helicase - repairs replication fork damage and double-strand breaks in mitosis - promotes repair through non-crossover mechanisms - dissolution of double Holliday junctions - promotes meiotic crossover patterning and homolog disjunction

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

Please see the JBrowse view of Dmel\Blm 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 Q9VGI8)

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
Comments on Gene Model

Gene model reviewed during 5.47

Sequence Ontology: Class of Gene
Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0082434
4806
1487
Additional Transcript Data and Comments
Reported size (kB)

4.835 (compiled cDNA)

2.4 (northern blot)

2.1 (northern blot)

Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
FBpp0081910
166.1
1487
8.71
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)

631 (aa); 65-70 (kD observed); 72 (kD predicted)

631 (aa); 69 (kD observed)

Comments
External Data
Subunit Structure (UniProtKB)

Monomer. Homodimer (via N-terminus). Homotetramer (via N-terminus); dimer of dimers. Homohexamer (via N-terminus). Self-association negatively regulates DNA unwinding amplitude and rate. Oligomer forms dissociate into monomer in presence of ATP.

(UniProt, Q9VGI8)
Domain

The N-terminal region mediates dimerization and homooligomerization. Both the helicase ATP-binding domain and the helicase C-terminal domain form intramolecular interactions with the HRDC domain in a ATP-dependent manner. The HRDC domain is required for single-stranded DNA (ssDNA) and DNA Holliday junction binding.

(UniProt, Q9VGI8)
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\Blm 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).

0.50

Transcript Expression
Additional Descriptive Data

Blm transcripts are observed at a low level through most of development on northern blots. They are abundant in ovaries, 0-2hr embryos, and adult females.

The Blm transcript is present in all stages, but is most abundant in early embryos and in ovaries.

Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Evidence
References
located_in nucleus
inferred from direct assay
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\Blm 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
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
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 11 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 7 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of Blm
Transgenic constructs containing regulatory region of Blm
Aberrations (Deficiencies and Duplications) ( 20 )
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
Sterility
Allele
Other Phenotypes
Allele
Phenotype manifest in
Allele
Orthologs
Human Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Homo sapiens (Human) (14)
11 of 14
Yes
Yes
1  
5 of 14
No
Yes
1  
3 of 14
No
No
3 of 14
No
No
3 of 14
No
Yes
1 of 14
No
No
1 of 14
No
No
1  
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1  
1 of 14
No
No
Model Organism Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Rattus norvegicus (Norway rat) (8)
10 of 14
Yes
Yes
5 of 14
No
Yes
3 of 14
No
No
3 of 14
No
No
3 of 14
No
Yes
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Mus musculus (laboratory mouse) (10)
11 of 14
Yes
Yes
4 of 14
No
Yes
3 of 14
No
No
3 of 14
No
No
3 of 14
No
Yes
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Xenopus tropicalis (Western clawed frog) (10)
8 of 13
Yes
Yes
2 of 13
No
Yes
2 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
Danio rerio (Zebrafish) (7)
11 of 14
Yes
Yes
4 of 14
No
Yes
2 of 14
No
No
2 of 14
No
No
2 of 14
No
Yes
1 of 14
No
No
1 of 14
No
No
Caenorhabditis elegans (Nematode, roundworm) (11)
12 of 14
Yes
Yes
4 of 14
No
Yes
3 of 14
No
No
3 of 14
No
Yes
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Anopheles gambiae (African malaria mosquito) (8)
10 of 12
Yes
Yes
Arabidopsis thaliana (thale-cress) (26)
10 of 13
Yes
Yes
10 of 13
Yes
Yes
6 of 13
No
Yes
5 of 13
No
Yes
3 of 13
No
No
3 of 13
No
No
3 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
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
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
Saccharomyces cerevisiae (Brewer's yeast) (10)
10 of 13
Yes
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
Yes
1 of 13
No
No
1 of 13
No
No
Schizosaccharomyces pombe (Fission yeast) (9)
9 of 12
Yes
Yes
2 of 12
No
Yes
2 of 12
No
No
2 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
Yes
1 of 12
No
No
Escherichia coli (enterobacterium) (1)
8 of 11
Yes
Yes
Other Organism Orthologs (via OrthoDB)
Data provided directly from OrthoDB:Blm. Refer to their site for version information.
Paralogs
Paralogs (via DIOPT v9.1)
Drosophila melanogaster (Fruit fly) (12)
5 of 13
5 of 13
1 of 13
1 of 13
1 of 13
1 of 13
1 of 13
1 of 13
1 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 ( 7 )
Potential Models Based on Orthology ( 2 )
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
esyN Network Diagram
Show neighbor-neighbor interactions:
Show/hide secondary interactors 
(data from AllianceMine provided by esyN)
Select Layout:
Legend:
Protein
RNA
Selected Interactor(s)
Other Interaction Browsers

Please see the Physical Interaction reports below for full details
RNA-RNA
Physical Interaction
Assay
References
protein-protein
Physical Interaction
Assay
References
Summary of Genetic Interactions
esyN Network Diagram
Show/hide secondary interactors 
(data from AllianceMine provided by esyN)
esyN Network Key:
Suppression
Enhancement
Other 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)
Monomer. Homodimer (via N-terminus). Homotetramer (via N-terminus); dimer of dimers. Homohexamer (via N-terminus). Self-association negatively regulates DNA unwinding amplitude and rate. Oligomer forms dissociate into monomer in presence of ATP.
(UniProt, Q9VGI8 )
Linkouts
BioGRID - A database of protein and genetic interactions.
DroID - A comprehensive database of gene and protein interactions.
MIST (genetic) - An integrated Molecular Interaction Database
MIST (protein-protein) - An integrated Molecular Interaction Database
Pathways
Signaling Pathways (FlyBase)
Metabolic Pathways
External Data
Linkouts
KEGG Pathways - A collection of manually drawn pathway maps representing knowledge of molecular interaction, reaction and relation networks.
Genomic Location and Detailed Mapping Data
Chromosome (arm)
3R
Recombination map
3-51
Cytogenetic map
Sequence location
FlyBase Computed Cytological Location
Cytogenetic map
Evidence for location
86E17-86E17
Limits computationally determined from genome sequence between P{PZ}tho1&P{PZ}l(3)0462905275 and P{EP}Lk6EP886
Experimentally Determined Cytological Location
Cytogenetic map
Notes
References
86F1-86F8
86F1-86F8
(determined by in situ hybridisation)
Experimentally Determined Recombination Data
Location
Left of (cM)
Right of (cM)
Notes
Stocks and Reagents
Stocks (15)
Genomic Clones (13)
 

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

cDNA Clones (23)
 

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
    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

        mus309 suppresses single strand annealing between divergent repeats (termed homologous SA), thereby preventing potentially deleterious recombination events.

        mus309, in collaboration with Top3α can resolve a mobile double Holliday junction substrate through convergent branch migration (in contrast to classic resolvase activities that use a structure-specific endonuclease to cleave the Holliday junctions).

        mus309 mutants are severely impaired in their ability to carry out repair DNA synthesis during synthesis-dependent strand annealing in double-strand break repair.

        Designation as "DmKu70" was in error.

        mus309 gene product is required for the repair of P-element induced double-strand DNA chromosome breaks, both in the presence and absence of a homologous sequence. Plasmid based P-element mobility assay demonstrates that the processing of double strand DNA breaks after P-element excision is severely affected in mus309 mutant embryos.

        Relationship to Other Genes
        Source for database merge of

        Source for merge of: mus309 blm

        Additional comments

        It had previously been suggested that mus309 corresponds to Irbp (FBrf0086898). Detailed deletion mapping suggests that this was incorrect and mus309 actually corresponds to blm, which is supported by the identification of mutations in the blm coding sequence for two mus309 alleles.

        mus309 stated to correspond to Irbp. Subsequent information suggests that this is not the case (see Kusano et al., 2001, Science 291(5513): 2600--2602).

        'Note added in proof' in FBrf0080432 was in error; mus309, l(3)87Ae and lds are not, in fact, allelic.

        Nomenclature History
        Source for database identify of

        Source for identity of: Blm mus309

        Nomenclature comments

        mus309' renamed to 'Blm' to reflect the preferred usage in the primary literature (see FBrf0155463, FBrf0216460, FBrf0193899, FBrf0207350, FBrf0107832, FBrf0135945, FBrf0180647, FBrf0200344, FBrf0179341, FBrf0191828, FBrf0202212, FBrf0193858, FBrf0209368). Moreover, symbols with 'mus' prefixes (for 'mutagen-sensitive') are deemed placeholders, to be replaced with a more meaningful symbol when available.

        Etymology
        Synonyms and Secondary IDs (30)
        Reported As
        Symbol Synonym
        mus 309
        Name Synonyms
        Bloom syndrome helicase
        Bloom syndrome helicase ortholog
        Bloom's helicase
        Drosophila Blm
        bloom syndrome helicase
        genome stabilizer 1
        mutagen-sensitive 309
        Secondary FlyBase IDs
        • FBgn0015800
        Datasets (0)
        Study focus (0)
        Experimental Role
        Project
        Project Type
        Title
        Study result (0)
        Result
        Result Type
        Title
        External Crossreferences and Linkouts ( 54 )
        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.
        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)
        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 (genetic) - An integrated Molecular Interaction Database
        MIST (protein-protein) - An integrated Molecular Interaction Database
        References (150)