SGS1 / YMR190C Overview

Standard Name
SGS1 1
Systematic Name
Feature Type
ORF , Verified
RecQ family nucleolar DNA helicase; role in genome integrity maintenance, chromosome synapsis, meiotic joint molecule/crossover formation; stimulates activity of Top3p; rapidly lost in response to rapamycin in Rrd1p-dependent manner; forms nuclear foci upon DNA replication stress; yeast SGS1 complements mutations in human homolog BLM implicated in Bloom syndrome; also similar to human WRN implicated in Werner syndrome; human BLM and WRN can each complement yeast null mutant 2 3 4 5 6 7 8 9 10 11 12 13
Name Description
Slow Growth Suppressor
Comparative Info
Sequence Details


The S. cerevisiae Reference Genome sequence is derived from laboratory strain S288C. Download DNA or protein sequence, view genomic context and coordinates. Click "Sequence Details" to view all sequence information for this locus, including that for other strains.

SGS1 is located on the right arm of chromsome XIII between GCV2 mitochondrial glycine decarboxylase complex subunit and SPG5 proteasome assembly protein; coding sequence is 4344 nucleotides long with 24 SNPs, 12 of which cause amino acid polymorphisms
Protein Details


Basic sequence-derived (length, molecular weight, isoelectric point) and experimentally-determined (median abundance, median absolute deviation) protein information. Click "Protein Details" for further information about the protein such as half-life, abundance, domains, domains shared with other proteins, protein sequence retrieval for various strains, physico-chemical properties, protein modification sites, and external identifiers for the protein.

Sgs1p is 1447 amino acids long and low in abundance; contains 4 helicase domains and an RQC domain; phosphorylated on 26 residues, sumoylated on 9 lysines; no identifiable domains in first half of protein
Length (a.a.)
Mol. Weight (Da)
Isoelectric Point
Median Abundance (molecules/cell)
120 +/- 115


Curated mutant alleles for the specified gene, listed alphabetically. Click on the allele name to open the allele page. Click "SGD search" to view all alleles in search results. Click "YeastMine" to view all alleles in YeastMine.

View all SGS1 alleles in SGD search | YeastMine

Gene Ontology Details

Gene Ontology

GO Annotations consist of four mandatory components: a gene product, a term from one of the three Gene Ontology (GO) controlled vocabularies (Molecular Function, Biological Process, and Cellular Component), a reference, and an evidence code. SGD has manually curated and high-throughput GO Annotations, both derived from the literature, as well as computational, or predicted, annotations. Click "Gene Ontology Details" to view all GO information and evidence for this locus as well as biological processes it shares with other genes.

Nucleolar ATP-dependent DNA helicase that is a subunit of the RecQ helicase-Topoisomerase III complex; melts and unwinds double-stranded DNA; involved in the formation of telomeric 3' overhangs, maintenance of telomeres by recombination, processing of DNA double-strand breaks, segregation of chromatids during mitosis, and segregation of chromosomes during meiosis; has a role in gene conversion at the mating-type loci, and also regulates meiotic recombination and the conversion of paired broken DNA and homologous duplex DNA into four-stranded branched intermediate joint molecules

View computational annotations

Molecular Function

Manually Curated

Cellular Component

Manually Curated


Macromolecular complex annotations are imported from the Complex Portal. These annotations have been derived from physical molecular interaction evidence extracted from the literature and cross-referenced in the entry, or by curator inference from information on homologs in closely related species or by inference from scientific background.

Phenotype Details


Phenotype annotations for a gene are curated single mutant phenotypes that require an observable (e.g., "cell shape"), a qualifier (e.g., "abnormal"), a mutant type (e.g., null), strain background, and a reference. In addition, annotations are classified as classical genetics or high-throughput (e.g., large scale survey, systematic mutation set). Whenever possible, allele information and additional details are provided. Click "Phenotype Details" to view all phenotype annotations and evidence for this locus as well as phenotypes it shares with other genes.

Non-essential gene; null mutant has an elevated rate of mutations and rate of gross chromosomal rearrangements, increased chromosome instability, and increased sensitivity to DNA damaging agents and UV light; null mutant has a decreased replicative lifespan but elevated caloric-restriction induced lifespan extension, and elevated chronological lifespan; null mutant has abnormal nuclear and nucleolar morphology, poor spore viability and decreased post-germination growth
Disease Details


Disease Annotations consist of three mandatory components: a gene product, a term from the Disease Ontology (DO) controlled vocabulary and an evidence code. SGD provides manually curated DO Annotations derived from the literature. Click "Disease Details" to view all Disease information and evidence for this locus as well as diseases it shares with other genes.

Yeast SGS1 is homologous to human BLM, ABCG4 and WRN, and has been used to study Bloom syndrome and Werner syndrome

Manually Curated

Interaction Details


Interaction annotations are curated by BioGRID and include physical or genetic interactions observed between at least two genes. An interaction annotation is composed of the interaction type, name of the interactor, assay type (e.g., Two-Hybrid), annotation type (e.g., manual or high-throughput), and a reference, as well as other experimental details. Click "Interaction Details" to view all interaction annotations and evidence for this locus, including an interaction visualization.

Sgs1p interacts physically with proteins involved in DNA repair; SGS1 interacts genetically with genes involved in transcription

4095 total interactions for 2352 unique genes

Physical Interactions

  • Affinity Capture-MS: 16
  • Affinity Capture-RNA: 3
  • Affinity Capture-Western: 37
  • Biochemical Activity: 12
  • Co-fractionation: 2
  • Co-localization: 1
  • Protein-peptide: 1
  • Reconstituted Complex: 9
  • Two-hybrid: 35

Genetic Interactions

  • Dosage Growth Defect: 5
  • Dosage Lethality: 2
  • Dosage Rescue: 14
  • Negative Genetic: 1411
  • Phenotypic Enhancement: 256
  • Phenotypic Suppression: 99
  • Positive Genetic: 1324
  • Synthetic Growth Defect: 291
  • Synthetic Lethality: 439
  • Synthetic Rescue: 138
Regulation Details


The number of putative Regulators (genes that regulate it) and Targets (genes it regulates) for the given locus, based on experimental evidence. This evidence includes data generated through high-throughput techniques. Click "Regulation Details" to view all regulation annotations, shared GO enrichment among regulation Targets, and a regulator/target diagram for the locus.

SGS1 promoter is bound by Fkh1p; SGS1 promoter is bound by Med2p, Med4p, Reb1p, and Tfc7p in response to heat; transcription of SGS1 is regulated by Spt10p
Expression Details


Expression data are derived from records contained in the Gene Expression Omnibus (GEO), and are first log2 transformed and normalized. Referenced datasets may contain one or more condition(s), and as a result there may be a greater number of conditions than datasets represented in a single clickable histogram bar. The histogram division at 0.0 separates the down-regulated (green) conditions and datasets from those that are up-regulated (red). Click "Expression Details" to view all expression annotations and details for this locus, including a visualization of genes that share a similar expression pattern.

Summary Paragraph

A summary of the locus, written by SGD Biocurators following a thorough review of the literature. Links to gene names and curated GO terms are included within the Summary Paragraphs.

Last Updated: 2000-03-10

Literature Details


All manually curated literature for the specified gene, organized into topics according to their relevance to the gene (Primary Literature, Additional Literature, or Review). Click "Literature Details" to view all literature information for this locus, including shared literature between genes.