Top3beta Topoisomerase 3beta [Drosophila melanogaster (fruit fly)] - Gene

Summary

Official Symbol: Top3betaprovided by FlyBase
Official Full Name: Topoisomerase 3betaprovided by FlyBase
Primary source: FLYBASE:FBgn0026015
Locus tag: Dmel_CG3458
See related: AllianceGenome:FB:FBgn0026015
Gene type: protein coding
RefSeq status: REVIEWED
Organism: Drosophila melanogaster
Lineage: Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Hexapoda; Insecta; Pterygota; Neoptera; Endopterygota; Diptera; Brachycera; Muscomorpha; Ephydroidea; Drosophilidae; Drosophila; Sophophora
Also known as: CG3458; Dmel\CG3458; dTop3beta; top3; Top3; TOP3; top3beta; top3[beta]; Topo IIIbeta; topo III[beta]
Summary: Enables DNA topoisomerase type I (single strand cut, ATP-independent) activity and RNA topoisomerase activity. Involved in DNA topological change; positive regulation of translation; and siRNA-mediated heterochromatin formation. Part of DNA topoisomerase III-beta-TDRD3 complex. Orthologous to human TOP3B (DNA topoisomerase III beta). [provided by Alliance of Genome Resources, Dec 2024]
Orthologs: all
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Genomic context

Location:: 5E5-5E5; 1-16 cM

Exon count:: 5

Annotation release	Status	Assembly	Chr	Location
Release 6.54	current	Release 6 plus ISO1 MT (GCF_000001215.4)	X	NC_004354.4 (6284138..6287990, complement)
Release 5.57	previous assembly	Release 5 (GCF_000001215.2)	X	NC_004354.3 (6178171..6182023, complement)

Chromosome X - NC_004354.4 Genomic Context describing neighboring genes

Genomic regions, transcripts, and products

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Go to reference sequence details

Genomic Sequence:

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Bibliography

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GeneRIFs: Gene References Into Functions

What's a GeneRIF?

Top3beta interacts biochemically and genetically with the RNAi-induced silencing complex (RISC) containing AGO2, p68 RNA helicase, and FMRP.
Title: Topoisomerase 3β interacts with RNAi machinery to promote heterochromatin formation and transcriptional silencing in Drosophila.
These results demonstrate that TDRD3 can enhance the biochemical activities of Top3beta on both DNA and RNA substrates, in addition to its function of targeting Top3beta to critical sites in subcellular compartments.
Title: DNA and RNA topoisomerase activities of Top3β are promoted by mediator protein Tudor domain-containing protein 3.
The results of this study suggested that Top3beta acts as an RNA topoisomerase and works with FMRP to promote the expression of mRNAs that are crucial for synapse formation.
Title: Top3β is an RNA topoisomerase that works with fragile X syndrome protein to promote synapse formation.
studies suggest that the topo III enzyme behaves as a structure-specific endonuclease in vivo, providing a reversible DNA cleavage activity that is specific for unpaired regions in the DNA
Title: Preferential cleavage of plasmid-based R-loops and D-loops by Drosophila topoisomerase IIIbeta.

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Interactions

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Products	Interactant	Other Gene	Complex	Source	Pubs	Description

General gene information

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Homology

NCBI Orthologs

Orthologs from OrthoDB

Gene Ontology Provided by FlyBase

Function	Evidence Code	Pubs
enables DNA binding	IEA Inferred from Electronic Annotation more info
enables DNA topoisomerase type I (single strand cut, ATP-independent) activity	IBA Inferred from Biological aspect of Ancestor more info
enables DNA topoisomerase type I (single strand cut, ATP-independent) activity	IDA Inferred from Direct Assay more info	PubMed
enables DNA topoisomerase type I (single strand cut, ATP-independent) activity	IEA Inferred from Electronic Annotation more info
enables RNA topoisomerase activity	IDA Inferred from Direct Assay more info	PubMed

Process	Evidence Code	Pubs
involved_in DNA recombination	IBA Inferred from Biological aspect of Ancestor more info
involved_in DNA repair	IBA Inferred from Biological aspect of Ancestor more info
involved_in DNA topological change	IBA Inferred from Biological aspect of Ancestor more info
involved_in DNA topological change	IDA Inferred from Direct Assay more info	PubMed
involved_in DNA topological change	IEA Inferred from Electronic Annotation more info
involved_in positive regulation of translation	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in siRNA-mediated heterochromatin formation	IGI Inferred from Genetic Interaction more info	PubMed

Component	Evidence Code	Pubs
part_of DNA topoisomerase III-beta-TDRD3 complex	IDA Inferred from Direct Assay more info	PubMed
part_of DNA topoisomerase III-beta-TDRD3 complex	IPI Inferred from Physical Interaction more info	PubMed
is_active_in nucleus	IBA Inferred from Biological aspect of Ancestor more info

General protein information

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Preferred Names: topoisomerase 3beta

Names: CG3458-PA; CG3458-PB; Top 3beta; Top3beta-PA; Top3beta-PB; drosophila topoisomerase 3beta; topoisomerase 3

NP_001284938.1

EC 5.6.2.1

NP_511059.2

EC 5.6.2.1

NCBI Reference Sequences (RefSeq)

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Genome Annotation

The following sections contain reference sequences that belong to a specific genome build. Explain

Reference assembly

Genomic

NC_004354.4 Reference assembly

Range

6284138..6287990 complement

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GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

NM_001298009.1 → NP_001284938.1 topoisomerase 3beta, isoform B [Drosophila melanogaster]

See identical proteins and their annotated locations for NP_001284938.1

Status: REVIEWED

UniProtKB/Swiss-Prot

O96651, Q5U0X6, Q9W416

UniProtKB/TrEMBL

X2JEB4

Conserved Domains (3) summary

cd03362
Location:4 → 166

TOPRIM_TopoIA_TopoIII; TOPRIM_TopoIA_TopoIII: The topoisomerase-primase (TORPIM) domain found in members of the type IA family of DNA topoisomerases (Topo IA) similar to topoisomerase III. Type IA DNA topoisomerases remove (relax) negative supercoils in the DNA by: cleaving ...

PRK07219
Location:4 → 781

PRK07219; DNA topoisomerase I; Validated

cd00186
Location:171 → 588

TOP1Ac; DNA Topoisomerase, subtype IA; DNA-binding, ATP-binding and catalytic domain of bacterial DNA topoisomerases I and III, and eukaryotic DNA topoisomerase III and eubacterial and archael reverse gyrases. Topoisomerases clevage single or double stranded DNA ...
NM_078504.4 → NP_511059.2 topoisomerase 3beta, isoform A [Drosophila melanogaster]

See identical proteins and their annotated locations for NP_511059.2

Status: REVIEWED

UniProtKB/Swiss-Prot

O96651, Q5U0X6, Q9W416

UniProtKB/TrEMBL

X2JEB4

Related

FBpp0070891

Conserved Domains (3) summary

cd03362
Location:4 → 166

TOPRIM_TopoIA_TopoIII; TOPRIM_TopoIA_TopoIII: The topoisomerase-primase (TORPIM) domain found in members of the type IA family of DNA topoisomerases (Topo IA) similar to topoisomerase III. Type IA DNA topoisomerases remove (relax) negative supercoils in the DNA by: cleaving ...

PRK07219
Location:4 → 781

PRK07219; DNA topoisomerase I; Validated

cd00186
Location:171 → 588

TOP1Ac; DNA Topoisomerase, subtype IA; DNA-binding, ATP-binding and catalytic domain of bacterial DNA topoisomerases I and III, and eukaryotic DNA topoisomerase III and eubacterial and archael reverse gyrases. Topoisomerases clevage single or double stranded DNA ...