L-threonine export: use of peptides to identify a new translocator from Corynebacterium glutamicum.

ABSTRACT: Bacterial mechanisms for the uptake of peptides and their hydrolysis to amino acids are known in great detail, whereas much less is known about the fates of the peptide-derived amino acids. We show that the addition of L-threonine-containing di- or tripeptides results in reduction of the growth of Corynebacterium glutamicum, with concomitant high intracellular accumulation of L-threonine to up to 130 mM. Using transposon mutagenesis and isolation of mutants with increased Thr peptide sensitivity, nine open reading frames (ORFs) were identified, almost all encoding hypothetical proteins of unknown function. Three ORFs encode membrane proteins. Their individual functional characterizations in the wild-type background led to the identification of thrE. Upon thrE overexpression, growth is no l

SUBMITTER: Simic P 

PROVIDER: S-EPMC95414 | biostudies-literature | 2001 Sep

REPOSITORIES: biostudies-literature