Any feedback?
Please rate this page
(ecexplorer.php)
(0/150)

BRENDA support

EC Explorer

EC 2.3.1.292 Details
EC number
2.3.1.292
Accepted name
(phenol)carboxyphthiodiolenone synthase
Reaction
(1) 3 malonyl-CoA + 2 (S)-methylmalonyl-CoA + icosanoyl-[(phenol)carboxyphthiodiolenone synthase] + 5 NADPH = C32-carboxyphthiodiolenone-[(phenol)carboxyphthiodiolenone synthase] + 5 CoA + 5 NADP+ + 5 CO2 + 2 H2O;;(2) 3 malonyl-CoA + 2 (S)-methylmalonyl-CoA + docosanoyl-[(phenol)carboxyphthiodiolenone synthase] + 5 NADPH = C34-carboxyphthiodiolenone-[(phenol)carboxyphthiodiolenone synthase] + 5 CoA + 5 NADP+ + 5 CO2 + 2 H2O;;(3) 3 malonyl-CoA + 2 (S)-methylmalonyl-CoA + 19-(4-hydroxyphenyl)-nonadecanoyl-[(phenol)carboxyphthiodiolenone synthase] + 5 NADPH = C37-(phenol)carboxyphthiodiolenone-[(phenol)carboxyphthiodiolenone synthase] + 5 CoA + 5 NADP+ + 5 CO2 + 2 H2O;;(4) 3 malonyl-CoA + 2 (S)-methylmalonyl-CoA + 17-(4-hydroxyphenyl)heptadecanoyl-[(phenol)carboxyphthiodiolenone synthase] + 5 NADPH = C35-(phenol)carboxyphthiodiolenone-[(phenol)carboxyphthiodiolenone synthase] + 5 CoA + 5 NADP+ + 5 CO2 + 2 H2O
Other name(s)
ppsABCDE (gene names)
Systematic name
(methyl)malonyl-CoA:long-chain acyl-[(phenol)carboxyphthiodiolenone synthase] (methyl)malonyltransferase {carboxyphthiodiolenone-[(phenol)carboxyphthiodiolenone synthase]-forming}
Comment
The enzyme, which is a complex of five polyketide synthase proteins, is involved in the synthesis of the lipid core common to phthiocerols and phenolphthiocerols. The first protein, PpsA, can accept either a C18 or C20 long-chain fatty acyl, or a (4-hydroxyphenyl)-C17 or C19 fatty acyl. The substrates must first be adenylated by EC 6.2.1.59, long-chain fatty acid adenylase/transferase FadD26, which also loads them onto PpsA. PpsA then extends them using a malonyl-CoA extender unit. The PpsB protein adds the next malonyl-CoA extender unit. The absence of a dehydratase and an enoyl reductase domains in the PpsA and PpsB modules results in the formation of the diol portion of the phthiocerol moiety. PpsC adds a third malonyl unit (releasing a water molecule due to its dehydratase domain), PpsD adds an (R)-methylmalonyl unit, releasing a water molecule, and PpsE adds a second (R)-methylmalonyl unit, without releasing a water molecule. The incorporation of the methylmalonyl units results in formation of two branched methyl groups in the elongated product. The enzyme does not contain a thioesterase domain [2], and release of the products requires the tesA-encoded type II thioesterase [1].
History
created 2019
EC Tree
2.3.1.55 created 1976, deleted 1999
2.3.1.120 created 1990, deleted 1992
2.3.1.124 created 1990, deleted 1992