ERG9/YHR190W Summary Help

Standard Name ERG9 1
Systematic Name YHR190W
Feature Type ORF, Verified
Description Farnesyl-diphosphate farnesyl transferase (squalene synthase); joins two farnesyl pyrophosphate moieties to form squalene in the sterol biosynthesis pathway (2, 3, 4 and see Summary Paragraph)
Name Description ERGosterol biosynthesis 1
Chromosomal Location
ChrVIII:484845 to 486179 | ORF Map | GBrowse
Gene Ontology Annotations All ERG9 GO evidence and references
  View Computational GO annotations for ERG9
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 9 genes
Classical genetics
Large-scale survey
39 total interaction(s) for 32 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 14
  • Affinity Capture-RNA: 2
  • Co-purification: 1
  • PCA: 13

Genetic Interactions
  • Negative Genetic: 5
  • Phenotypic Enhancement: 2
  • Positive Genetic: 2

Expression Summary
Length (a.a.) 444
Molecular Weight (Da) 51,719
Isoelectric Point (pI) 5.79
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrVIII:484845 to 486179 | ORF Map | GBrowse
Last Update Coordinates: 2005-11-07 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1335 484845..486179 2005-11-07 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | E.C. | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000001233

ERG9 encodes farnesyl-diphosphate farnesyl transferase (also called squalene synthase), an enzyme that joins two farnesyl pyrophosphate moieties to form squalene, a reaction in the sterol biosynthesis pathway (3, 2, 4, 5, 6). erg9 null mutants lack farnesyl-diphosphate farnesyl transferase activity (2), and are ergosterol auxotrophs (7). Synthesis of polyprenols is elevated in erg9 mutants, suggesting that Erg9p may have a regulatory role (7). ERG9 expression is increased by mutations in genes encoding other sterol biosynthetic enzymes (8). The erg9 null phenotype can be complemented by expression of homolgos from S. pombe, Nicotiana benthamiana, and Yarrowia lipolytica (9, 10, 11).

Last updated: 2000-08-29 Contact SGD

References cited on this page View Complete Literature Guide for ERG9
1) Karst F and Lacroute F  (1977) Ertosterol biosynthesis in Saccharomyces cerevisiae: mutants deficient in the early steps of the pathway. Mol Gen Genet 154(3):269-77
2) Jennings SM, et al.  (1991) Molecular cloning and characterization of the yeast gene for squalene synthetase. Proc Natl Acad Sci U S A 88(14):6038-42
3) Fegueur M, et al.  (1991) Isolation and primary structure of the ERG9 gene of Saccharomyces cerevisiae encoding squalene synthetase. Curr Genet 20(5):365-72
4) Paltauf F, et al.  (1992) "Regulation and compartmentalization of lipid synthesis in yeast." Pp. 415-500 in The Molecular and Cellular Biology of the Yeast Saccharomyces: Gene Expression, edited by Jones EW, Pringle JR and Broach JR. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory Press
5) Parks LW, et al.  (1995) Biochemical and physiological effects of sterol alterations in yeast--a review. Lipids 30(3):227-30
6) Stryer L  (1995) Biochemistry (4th ed.). New York: W. H. Freeman and Company
7) Grabowska D, et al.  (1998) Effect of squalene synthase gene disruption on synthesis of polyprenols in Saccharomyces cerevisiae. FEBS Lett 434(3):406-8
8) Kennedy MA, et al.  (1999) Transcriptional regulation of the squalene synthase gene (ERG9) in the yeast Saccharomyces cerevisiae. Biochim Biophys Acta 1445(1):110-22
9) Robinson GW, et al.  (1993) Conservation between human and fungal squalene synthetases: similarities in structure, function, and regulation. Mol Cell Biol 13(5):2706-17
10) Hanley KM, et al.  (1996) Molecular cloning, in vitro expression and characterization of a plant squalene synthetase cDNA. Plant Mol Biol 30(6):1139-51
11) Merkulov S, et al.  (2000) Cloning and characterization of the Yarrowia lipolytica squalene synthase (SQS1) gene and functional complementation of the Saccharomyces cerevisiae erg9 mutation. Yeast 16(3):197-206