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ENZYME

ENZYME entry: EC 2.3.1.328

PURL: https://purl.expasy.org/enzyme/EC/2.3.1.328
Accepted Name
branched-chain 2-oxoacid:malonyl-[acyl-carrier protein] acyltransferase
Reaction catalysed
N(6)-[(R)-lipoyl]-L-lysyl-[lipoyl-carrier protein] + 4-methyl-2-oxopentanoate + malonyl-[ACP] + 2 H(+) = 5-methyl-3-oxohexanoyl-[ACP] + N(6)-[(R)-dihydrolipoyl]-L-lysyl-[lipoyl-carrier protein] + 2 CO2
Comment(s)
  • The enzyme, characterized from an environmental DNA sample and expressed in Paraburkholderia graminis, is a complex enzyme whose purpose is to divert branched-chain 2-oxo acids to production of branched-chain N-acyl amino acids by producing branched 3-oxoacyl- [ACP] molecules.
  • NasB accepts branched-chain 2-oxoacids such as 4-methyl-2- oxopentanoate, and catalyzes a decarboxylative transfer to a thiamine diphosphate cofactor, followed by a transfer to a lipoyl cofactor, and finally a second decarboxylative transfer to the malonyl-[ACP] acceptor.
  • The products, such as 5-methyl-3-oxohexanoyl-[ACP], can be extended by the fatty acid synthase system to form branched long-chain fatty- acyl-[ACP] molecules, which serve as substrates for EC 2.3.1.327.
  • During the reaction the lipoyl cofactor is reduced to dihydrolipoyl, which must be oxidized back to lipoyl by an unknown enzyme.
Cross-references
BRENDA2.3.1.328
EC2PDB2.3.1.328
ExplorEnz2.3.1.328
KEGG Ligand Database for Enzyme Nomenclature2.3.1.328
IUBMB Enzyme Nomenclature2.3.1.328
MEDLINEFind literature relating to 2.3.1.328
MetaCyc2.3.1.328
Rhea expert-curated reactions2.3.1.328

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All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 2.3.1.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 2.3.-.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 2.-.-.-