BCS1 / YDR375C Overview

Standard Name
BCS1 1
Systematic Name
Feature Type
ORF , Verified
Protein translocase and chaperone required for Complex III assembly; member of the AAA ATPase family; forms a homo-oligomeric complex in the mitochondrial inner membrane that translocates the C-terminal domain of Rip1p from the matrix across the inner membrane and delivers it to an assembly intermediate of respiratory Complex III; also required for assembly of the Qcr10p subunit; mutation is functionally complemented by human homolog BCS1L, linked to neonatal diseases 2 3 4
Name Description
ubiquinol-cytochrome c reductase (bc1) Synthesis 1
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.

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.

Member of the AAA ATPase family; forms a homo-oligomeric complex in the mitochondrial inner membrane
Length (a.a.)
Mol. Weight (Da)
Isoelectric Point
Median Abundance (molecules/cell)
1538 +/- 813
Half-life (hr)


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 BCS1 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.

Transporter with ATPase activity that acts as chaperone in the assembly of mitochondrial respiratory chain complex III; localizes in mitochondrial inner membrane

View computational annotations

Cellular Component

Manually Curated
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 and point mutants fail to respire and exhibit mitochondrial genome instability and decreased chronological lifespan; in large-scale studies, the null mutant shows reduced competitive fitness, sensitivity to desiccation, heat, and oxidative stress, and sensitivity to various chemicals
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 BCS1 is homologous to human BCS1L, and has been used to study mitochondrial complex III deficiency nuclear type 1
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.

299 total interactions for 224 unique genes

Physical Interactions

  • Affinity Capture-MS: 6
  • Affinity Capture-RNA: 6
  • Affinity Capture-Western: 6
  • Co-crystal Structure: 2
  • Reconstituted Complex: 1

Genetic Interactions

  • Dosage Growth Defect: 1
  • Dosage Rescue: 1
  • Negative Genetic: 255
  • Phenotypic Suppression: 1
  • Positive Genetic: 13
  • Synthetic Growth Defect: 3
  • Synthetic Lethality: 1
  • Synthetic Rescue: 3
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.

BCS1 encodes a mitochondrial AAA ATPase that is essential for respiratory growth. Bcs1p is integral to the mitochondrial inner membrane and plays a key role in the assembly of the cytochrome bc1 complex (complex III) of the mitochondrial respiratory chain. One of the essential subunits of the cytochrome bc1 complex is Rip1p - a Rieske iron-sulfur protein with a ubiquinol-cytochrome-c reductase activity that transfers electrons from ubiquinol to cytochrome c1 during respiration. The precursor of Rip1p is synthesized in the cytosol and imported into the mitochondrial matrix, where it binds a 2Fe2S cluster via its C-terminal domain. Bcs1p mediates the transport of the folded FeS-containing C-terminal domain of Rip1p across the inner membrane into the intermembrane space and subsequently integrates Rip1p into the bc1 precomplex. This last step depends on the hydrolysis of Bcs1p-bound ATP, which provides a regulatory loop that links the rate of complex III biogenesis to the energy-producing activity of mitochondria. Increased activity leads to increased ATP levels, which in turn stimulates the Bcs1p-mediated complex III assembly. Human homolg BCS1L is associated with multiple genetic disorders, including Mitochondrial Complex III Deficiency, Bjornstad Syndrome and GRACILE syndrome.
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.

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.