D-Pantothenate synthesis in Corynebacterium glutamicum and use of panBC and genes encoding L-valine synthesis for D-pantothenate overproduction.

ABSTRACT: D-Pantothenate is synthesized via four enzymes from ketoisovalerate, which is an intermediate of branched-chain amino acid synthesis. We quantified three of these enzyme activities in Corynebacterium glutamicum and determined specific activities ranging from 0.00014 to 0.001 micromol/min mg (protein)-1. The genes encoding the ketopantoatehydroxymethyl transferase and the pantothenate synthetase were cloned, sequenced, and functionally characterized. These studies suggest that panBC constitutes an operon. By using panC, an assay system was developed to quantify D-pantothenate. The wild type of C. glutamicum was found to accumulate 9 micrograms of this vitamin per liter. A strain was constructed (i) to abolish L-isoleucine synthesis, (ii) to result in increased ketoisovalerate formation, and

SUBMITTER: Sahm H 

PROVIDER: S-EPMC91285 | biostudies-literature | 1999 May

REPOSITORIES: biostudies-literature