Analysis of a Corynebacterium glutamicum hom gene coding for a feedback-resistant homoserine dehydrogenase

Abstract

From a Corynebacterium glutamicum mutant possessing a homoserine dehydrogenase resistant to feedback inhibition by L-threonine, the corresponding gene (hom(FBR)) was analyzed and compared with the wild-type hom gene. DNA fragment exchange experiments between both genes showed that a 0.23-kb region close to the 3' terminus of hom(FBR) was responsible for deregulation. Nucleotide sequence analysis revealed a single transition from G to A in hom(FBR) leading to replacement of glycine-378 by glutamate in the mutant homoserine dehydrogenase.