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MetaCyc Enzyme: very-long-chain 3-oxoacyl-CoA synthase

Gene: ELO3 Accession Numbers: G-15116 (MetaCyc), YLR372W

Synonyms: SUR4, APA1, SRE1, VBM1

Species: Saccharomyces cerevisiae

Summary:
Very-long-chain fatty acids (VLCFAs) are synthesized as acyl-CoAs by the endoplasmic reticulum-localized elongase multiprotein complex.

The ELO2 gene of Saccharomyces cerevisiae encodes one of two condensing enzymes that participate in the elongase complex (the other enzyme is encoded by ELO3). These enzymes catalyze the first reaction of the elongase cycle in which the two carbons that originate from malonyl-CoA are condensed to the growing acyl-CoA moiety [Oh97]. Both ELO2 and ELO3 are homologs of ELO1, which is responsible for extending fatty acids up to palmitate (16 carbons) and stearate (18 carbons) [Toke96, Dittrich98].

Disruption of either gene reduces cellular sphingolipid levels and results in the accumulation of the long chain base, phytosphingosine. The simultaneous disruption of ELO2 and ELO3 has been shown to produce synthetic lethality. Gas chromatography and gas chromatography/mass spectroscopy analyses showed that null mutants for ELO2 and ELO3 are defective in the formation of VLCFAs [Oh97, Rossler03].

ELO2 appears to be involved in the elongation of fatty acids up to behenate (22 carbons), while ELO3 has a broader substrate specificity, and is thus essential for production of lignocerate (24-carbon) and cerotate (26-carbon) [Oh97].

Proteoliposomes reconstituted from the four elongase complex components of Saccharomyces cerevisiae, including either ELO2 or ELO3, catalyzed repeated rounds of two-carbon addition that elongated shorter fatty acids into VLCFAs whose length was dictated by the specific synthase homolog present (yeast has three elongase-specific synthases) [Denic07].

Locations: endoplasmic reticulum membrane

Molecular Weight of Polypeptide: 39.465 kD (from nucleotide sequence)

Unification Links: DIP:DIP-4024N , Entrez-gene:851087 , Mint:MINT-505805 , Protein Model Portal:P40319 , String:4932.YLR372W , UniProt:P40319

Relationship Links: InterPro:IN-FAMILY:IPR002076 , Panther:IN-FAMILY:PTHR11157 , Pfam:IN-FAMILY:PF01151 , Prosite:IN-FAMILY:PS01188

Gene-Reaction Schematic: ?

GO Terms:

Cellular Component: GO:0005789 - endoplasmic reticulum membrane Traceable author statement to experimental support [Rossler03]

Credits:
Created 06-Apr-2012 by Caspi R , SRI International


Enzymatic reaction of: 3-oxo-cerotoyl-CoA synthase (very-long-chain 3-oxoacyl-CoA synthase)

lignoceroyl-CoA + malonyl-CoA + H+ <=> 3-oxo-cerotoyl-CoA + CO2 + coenzyme A

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is favored in the direction shown.

In Pathways: very long chain fatty acid biosynthesis II


Enzymatic reaction of: 3-oxo-lignoceronyl-CoA synthase (very-long-chain 3-oxoacyl-CoA synthase)

docosanoyl-CoA + malonyl-CoA + H+ <=> 3-oxo-lignoceroyl-CoA + CO2 + coenzyme A

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is favored in the direction shown.

In Pathways: very long chain fatty acid biosynthesis II


Enzymatic reaction of: 3-oxo-behenoyl-CoA synthase (very-long-chain 3-oxoacyl-CoA synthase)

arachidoyl-CoA + malonyl-CoA + H+ <=> 3-oxo-behenoyl-CoA + CO2 + coenzyme A

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is favored in the direction shown.

In Pathways: very long chain fatty acid biosynthesis II


Enzymatic reaction of: 3-oxo-arachidoyl-CoA synthase (very-long-chain 3-oxoacyl-CoA synthase)

stearoyl-CoA + malonyl-CoA + H+ <=> 3-oxo-arachidoyl-CoA + CO2 + coenzyme A

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is favored in the direction shown.

In Pathways: very long chain fatty acid biosynthesis II


References

Denic07: Denic V, Weissman JS (2007). "A molecular caliper mechanism for determining very long-chain fatty acid length." Cell 130(4);663-77. PMID: 17719544

Dittrich98: Dittrich F, Zajonc D, Huhne K, Hoja U, Ekici A, Greiner E, Klein H, Hofmann J, Bessoule JJ, Sperling P, Schweizer E (1998). "Fatty acid elongation in yeast--biochemical characteristics of the enzyme system and isolation of elongation-defective mutants." Eur J Biochem 252(3);477-85. PMID: 9546663

Oh97: Oh CS, Toke DA, Mandala S, Martin CE (1997). "ELO2 and ELO3, homologues of the Saccharomyces cerevisiae ELO1 gene, function in fatty acid elongation and are required for sphingolipid formation." J Biol Chem 272(28);17376-84. PMID: 9211877

Rossler03: Rossler H, Rieck C, Delong T, Hoja U, Schweizer E (2003). "Functional differentiation and selective inactivation of multiple Saccharomyces cerevisiae genes involved in very-long-chain fatty acid synthesis." Mol Genet Genomics 269(2);290-8. PMID: 12684876

Toke96: Toke DA, Martin CE (1996). "Isolation and characterization of a gene affecting fatty acid elongation in Saccharomyces cerevisiae." J Biol Chem 271(31);18413-22. PMID: 8702485


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 18.5 on Thu Dec 18, 2014, BIOCYC14B.