topoisomerase I, Topo I, l(1)G0229, TopoI, l(1)G0278
Please see the JBrowse view of Dmel\Top1 for information on other features
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AlphaFold produces a per-residue confidence score (pLDDT) between 0 and 100. Some regions with low pLDDT may be unstructured in isolation.
Gene model reviewed during 5.50
Low-frequency RNA-Seq exon junction(s) not annotated.
Annotated transcripts do not represent all possible combinations of alternative exons and/or alternative promoters.
Gene model reviewed during 5.39
Gene model reviewed during 5.55
5.2, 4.0 (northern blot)
5.2, 4.0 (unknown)
Homology to other Top1 proteins is concentrated in two regions. The Drosophila enzyme is larger than the enzymes from yeast and human and is uniquely characterized by a Ser/His rich hydrophilic domain of 200aa at its amino terminus. The bacterially expressed protein was shown to have classic eukaryotic DNA topoisomerase I activity, distinguished by the fact that it can relax both positively and negatively supercoiled DNA in the absence of a divalent cation.
Camptothecin-induced Top1 protein cleavage sites were mapped in the Act5C, Act57B, and hsp70 genes. Top1 protein cleavage sites were localized to the transcribed portions of the Hsp70B and Act5C genes, and only when they are transcriptionally active. None were found in a transcriptionally inactive Act57B gene.
Interacts with Topors.
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Top1 using the Feature Mapper tool.
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).
A substantial amount of maternally derived Top1 protein is present in early embryos. Protein levels peak at 6-12 hours and decline to near zero in pupae. Some expression is observed in the ovary.
JBrowse - Visual display of RNA-Seq signals
View Dmel\Top1 in JBrowsePlease Note FlyBase no longer curates genomic clone accessions so this list may not be complete
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.
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.
DNA-protein interactions: genome-wide binding profile assayed for Top1 protein in Kc167 cells; see Chromatin_types_NKI collection report. Individual protein-binding experiments listed under "Samples" at GEO_GSE22069 (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE22069).
Top1 plays an essential role in many developmental stages active in cell proliferation.
The genomic organisation of the Top1 locus has been determined and its expression pattern has been analysed.
Using P element mutagenesis a mutant deficient in topoisomerase 1 was generated: topoisomerase 1 is essential for growth and development.
Top1 has been isolated and partially characterised.
DNA topoisomerase 1 was cloned by homology to consensus eukaryotic DNA topoisomerase 1 sequence, and expressed in an E.coli expression system.
The interaction of Top1 and Top2 gene products with transcriptionally active and inactive Act5C, Act57B and Hsp70B has been compared. Topoisomerase I binding sites are found in the transcribed portions of the Hsp70B and Act5C genes, and only when they are transcriptionally active. It does not associate with a transcriptionally inactive Act57B gene.
Top1 enzyme has been purified and characterised.
Source for merge of: Top1 l(1)G0229 l(1)G0278 l(1)G0134 l(1)G0201
Source for identity of: Top1 CG6146
