TOP1 DNA topoisomerase 1 [Saccharomyces cerevisiae S288C] - Gene

Summary

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Official Symbol: TOP1
Official Full Name: DNA topoisomerase 1
Primary source: SGD:S000005366
Locus tag: YOL006C
See related: AllianceGenome:SGD:S000005366; FungiDB:YOL006C; VEuPathDB:YOL006C
Gene type: protein coding
RefSeq status: REVIEWED
Organism: Saccharomyces cerevisiae S288C (strain: S288C)
Lineage: Eukaryota; Fungi; Dikarya; Ascomycota; Saccharomycotina; Saccharomycetes; Saccharomycetales; Saccharomycetaceae; Saccharomyces
Also known as: MAK1; MAK17
Summary: Enables DNA topoisomerase type I (single strand cut, ATP-independent) activity. Involved in several processes, including DNA-templated transcription; chromosome organization; and regulation of gene expression. Located in nucleolus. Part of replication fork protection complex. Used to study cancer. Orthologous to human TOP1 (DNA topoisomerase I) and TOP1MT (DNA topoisomerase I mitochondrial). [provided by Alliance of Genome Resources, Dec 2024]
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Genomic context

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See TOP1 in Genome Data Viewer

Location:: chromosome: XV

Exon count:: 1

Sequence:: Chromosome: XV; NC_001147.6 (313078..315387, complement)

Chromosome XV - NC_001147.6 Genomic Context describing neighboring genes

Genomic regions, transcripts, and products

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Go to reference sequence details

Genomic Sequence:: NC_001147.6

Go to nucleotide: Graphics FASTA GenBank

Bibliography

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GeneRIFs: Gene References Into Functions

What's a GeneRIF?

Molecular basis for processing of topoisomerase 1-triggered DNA damage by Apn2/APE2.
Title: Molecular basis for processing of topoisomerase 1-triggered DNA damage by Apn2/APE2.
Topoisomerases Modulate the Timing of Meiotic DNA Breakage and Chromosome Morphogenesis in Saccharomyces cerevisiae.
Title: Topoisomerases Modulate the Timing of Meiotic DNA Breakage and Chromosome Morphogenesis in Saccharomyces cerevisiae.
Fob1p recruits DNA topoisomerase I to ribosomal genes locus and contributes to its transcriptional silencing maintenance
Title: Fob1p recruits DNA topoisomerase I to ribosomal genes locus and contributes to its transcriptional silencing maintenance.
Studies demonstrate opposing roles of Top1 activity in either promoting or destabilizing genome integrity. Resolution of transcription-associated negative supercoils, for example, prevents pairing of the nascent RNA with the DNA template (R-loops) as well as DNA secondary structure formation. Reduced Top1 levels thus enhance CAG repeat contraction, somatic hypermutation, and class switch recombination.
Title: Topoisomerase I and Genome Stability: The Good and the Bad.
Our findings reveal a requirement for the Smc5/6 complex, including Mms21/Nse2 mediated sumoylation, and topoisomerase-1 (Top1), for maintaining stability of a chromosome having low origin density and suggest a functional cooperation between the Smc5/6 complex and Top1 in maintenance of topologically challenged chromosomes prone to replication fork collapse or accumulation of torsional stress
Title: Genetic evidence for functional interaction of Smc5/6 complex and Top1 with spatial frequency of replication origins required for maintenance of chromosome stability.
Our findings reveal a functional interplay between Mms21 and Top1 in maintenance of longer chromosomes, and suggest that lack of sumoylation of Mms21 targets coupled with Top1 deficiency is a crucial requirement for accurate inheritance of longer chromosomes.
Title: Interplay between Top1 and Mms21/Nse2 mediated sumoylation in stable maintenance of long chromosomes.
Too much, as well as too little of Top1 is detrimental to eukaryotic genomes, and that CPT has destabilizing effects that extend beyond those associated with DSB formation.
Title: Effects of camptothecin or TOP1 overexpression on genetic stability in Saccharomyces cerevisiae.
The authors demonstrate biochemically that irreversible double-strand breaks are generated by subsequent Top1 cleavage on the opposite strand from the Top1-induced DNA nicks at ribonucleotide sites.
Title: Topoisomerase I-mediated cleavage at unrepaired ribonucleotides generates DNA double-strand breaks.
These genetic and biochemical studies support a model whereby Top1p recruits Sir2p to the rDNA and clarifies a structural role of DNA topoisomerase I in the epigenetic regulation of rDNA, independent of its known catalytic activity.
Title: Molecular Mechanism of DNA Topoisomerase I-Dependent rDNA Silencing: Sir2p Recruitment at Ribosomal Genes.
The role of topoisomerase I in suppressing genome instability associated with a highly transcribed guanine-rich sequence is not restricted to preventing RNA:DNA hybrid accumulation.
Title: The role of topoisomerase I in suppressing genome instability associated with a highly transcribed guanine-rich sequence is not restricted to preventing RNA:DNA hybrid accumulation.

Submit: New GeneRIF Correction See all GeneRIFs (27)

Pathways from PubChem

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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

Orthologs from OrthoDB

Gene Ontology Provided by SGD

Function	Evidence Code	Pubs
enables DNA binding	IEA Inferred from Electronic Annotation more info
enables DNA topoisomerase activity	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 DNA topoisomerase type I (single strand cut, ATP-independent) activity	IMP Inferred from Mutant Phenotype more info	PubMed

Process	Evidence Code	Pubs
involved_in DNA replication	IBA Inferred from Biological aspect of Ancestor more info
involved_in DNA strand elongation involved in DNA replication	IMP Inferred from Mutant Phenotype more info	PubMed
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 DNA topological change	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in chromatin organization	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in chromosome segregation	IBA Inferred from Biological aspect of Ancestor more info
involved_in mitotic chromosome condensation	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in nuclear migration	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in rDNA heterochromatin formation	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in rRNA transcription	IGI Inferred from Genetic Interaction more info	PubMed
involved_in regulation of mitotic recombination	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in regulation of transcription by RNA polymerase II	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in transcription elongation by RNA polymerase II	IMP Inferred from Mutant Phenotype more info	PubMed

Component	Evidence Code	Pubs
located_in chromosome	IEA Inferred from Electronic Annotation more info
is_active_in nucleolus	IBA Inferred from Biological aspect of Ancestor more info
located_in nucleolus	IEA Inferred from Electronic Annotation more info
located_in nucleolus	IPI Inferred from Physical Interaction more info	PubMed
located_in nucleoplasm	IEA Inferred from Electronic Annotation more info
located_in nucleus	IDA Inferred from Direct Assay more info	PubMed
located_in nucleus	IEA Inferred from Electronic Annotation more info
part_of replication fork protection complex	IDA Inferred from Direct Assay more info	PubMed

General protein information

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Preferred Names: DNA topoisomerase 1

NP_014637.1

EC 5.6.2.1

Topoisomerase I; nuclear enzyme that relieves torsional strain in DNA by cleaving and re-sealing the phosphodiester backbone; relaxes both positively and negatively supercoiled DNA; functions in replication, transcription, and recombination; role in processing ribonucleoside monophosphates in genomic DNA into irreversible single-strand breaks; enzymatic activity and interaction with Nsr1p are negatively regulated by polyphosphorylation

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_001147.6 Reference assembly

Range

313078..315387 complement

Download

GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

NM_001183260.1 → NP_014637.1 TPA: DNA topoisomerase 1 [Saccharomyces cerevisiae S288C]

See identical proteins and their annotated locations for NP_014637.1

Status: REVIEWED

UniProtKB/Swiss-Prot

D6W261, P04786

UniProtKB/TrEMBL

A6ZNK0, B3LJ50, B5VRP8, C8ZHV9, N1NVQ3

Conserved Domains (2) summary

smart00435
Location:292 → 741

TOPEUc; DNA Topoisomerase I (eukaryota)

pfam02919
Location:143 → 361

Topoisom_I_N; Eukaryotic DNA topoisomerase I, DNA binding fragment