Reaction: 2 malonyl-CoA + [2-methylbutanoate polyketide synthase] + 2 NADPH + 3 H+ + S-adenosyl-L-methionine = (S)-2-methylbutanoyl-[2-methylbutanoate polyketide synthase] + 2 CoA + 2 CO2 + 2 NADP+ + S-adenosyl-L-homocysteine + H2O
For diagram of reaction click here.
Other name(s): LovF
Systematic name: acyl-CoA:malonyl-CoA C-acyltransferase (2-methylbutanoate-forming)
Comments: This polyketide synthase enzyme forms the (S)-2-methylbutanoate side chain during lovastatin biosynthesis by the filamentous fungus Aspergillus terreus. The overall reaction comprises a single condensation reaction followed by α-methylation, β-ketoreduction, dehydration, and α,β-enoyl reduction.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
1. Kennedy, J., Auclair, K., Kendrew, S.G., Park, C., Vederas, J.C. and Hutchinson, C.R. Modulation of polyketide synthase activity by accessory proteins during lovastatin biosynthesis. Science 284 (1999) 1368-1372. [PMID: 10334994]
2. Meehan, M.J., Xie, X., Zhao, X., Xu, W., Tang, Y. and Dorrestein, P.C. FT-ICR-MS characterization of intermediates in the biosynthesis of the α-methylbutyrate side chain of lovastatin by the 277 kDa polyketide synthase LovF. Biochemistry 50 (2011) 287-299. [PMID: 21069965]