[dihydrolipoyllysine-residue (2-methylpropanoyl)transferase] S-(2-methylpropanoyl)dihydrolipoyllysine [CPD:C15977];
Contains thiamine diphosphate. It acts not only on 3-methyl-2-oxobutanaoate, but also on 4-methyl-2-oxopentanoate and (S)-3-methyl-2-oxopentanoate, so that it acts on the 2-oxo acids that derive from the action of transaminases on valine, leucine and isoleucine. It is a component of the multienzyme 3-methyl-2-oxobutanoate dehydrogenase complex in which multiple copies of it are bound to a core of molecules of EC 184.108.40.206, dihydrolipoyllysine-residue (2-methylpropanoyl)transferase, which also binds multiple copies of EC 220.127.116.11, dihydrolipoyl dehydrogenase. It does not act on free lipoamide or lipoyllysine, but only on the lipoyllysine residue in EC 18.104.22.168.
EC 22.214.171.124 created 1972 (EC 126.96.36.199 created 1972, incorporated 1978), modified 2003