ERG10 (YPL028W, P41338) notes

Identity and activity

• Acetyl-CoA C-acetyltransferase (acetoacetyl-CoA thiolase, EC 2.3.1.9); condenses 2 acetyl-CoA to acetoacetyl-CoA, step 1 of the mevalonate pathway [UniProt:P41338 "Reaction=2 acetyl-CoA = acetoacetyl-CoA + CoA; Xref=Rhea:RHEA:21036,"].
• Gene identified in a screen for mevalonate auxotrophs; null alleles have no detectable acetoacetyl-CoA thiolase activity; essential single-copy gene PMID:7989303, PMID:7989303.
• Active-site cysteines C91 and C384 conserved with other thiolases PMID:7989303.
• Biochemical characterisation of yeast thiolase forms: PMID:5571829 (abstract not cached; title only). UniProt kinetic data (Km CoA 0.16 mM) attributed to it.
• Homotetramer [UniProt:P41338 "SUBUNIT: Homotetramer."].

Location

• Cytosolic [UniProt:P41338 "SUBCELLULAR LOCATION: Cytoplasm, cytosol"]; cytoplasmic per Hiser et al. PMID:7989303.
• Huh et al. GFP survey (HDA nucleus); likely nucleocytoplasmic diffuse signal of a soluble enzyme; non-core.
• Vacuole NAS from a 2017 review (PMID:28904410); cached text has no vacuole statement for Erg10; contradicted by experimental cytosolic location.

Pathways

• Mevalonate pathway -> ergosterol; UniProt: [UniProt:P41338 "Metabolic intermediate biosynthesis; (R)-mevalonate"].
• Physiological direction is condensation (left-to-right) [UniProt:P41338 "PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:21037;"].
• YeastPathways also places Erg10 in PWY-5177 (glutaryl-CoA degradation), the thiolytic cleavage of acetoacetyl-CoA. S. cerevisiae has no characterised glutaryl-CoA dehydrogenase/lysine degradation route; no yeast evidence that Erg10 functions in lysine/glutaryl-CoA catabolism. The MF is correct but the catabolic BP is a pathway-template inference.
• Karst & Lacroute 1977 (PMID:200835) early erg mutants: abstract groups erg10 with squalene synthetase deficiency (historical allele nomenclature differs); curator IMP for ergosterol biosynthesis is consistent with the essential role of Erg10 in sterol synthesis.

Expression / phenotype

• Induced by low sterol and by cold; deletion/disruption gives cold and freeze sensitivity [UniProt:P41338 "Leads to cold and freeze sensitivity."].