Arabidopsis thaliana encodes a bacterial-type heterodimeric isopropylmalate isomerase involved in both Leu biosynthesis and the Met chain elongation pathway of glucosinolate formation.

ABSTRACT: The last steps of the Leu biosynthetic pathway and the Met chain elongation cycle for glucosinolate formation share identical reaction types suggesting a close evolutionary relationship of these pathways. Both pathways involve the condensation of acetyl-CoA and a 2-oxo acid, isomerization of the resulting 2-malate derivative to form a 3-malate derivative, the oxidation-decarboxylation of the 3-malate derivative to give an elongated 2-oxo acid, and transamination to generate the corresponding amino acid. We have now analyzed the genes encoding the isomerization reaction, the second step of this sequence, in Arabidopsis thaliana. One gene encodes the large subunit and three encode small subunits of this enzyme, referred to as isopropylmalate isomerase (IPMI) with respect to the Leu pathway.

SUBMITTER: Knill T 

PROVIDER: S-EPMC2729411 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature