Aspartate kinase-independent lysine synthesis in an extremely thermophilic bacterium, Thermus thermophilus: lysine is synthesized via alpha-aminoadipic acid not via diaminopimelic acid.

ABSTRACT: An aspartate kinase-deficient mutant of Thermus thermophilus, AK001, was constructed. The mutant strain did not grow in a minimal medium, suggesting that T. thermophilus contains a single aspartate kinase. Growth of the mutant strain was restored by addition of both threonine and methionine, while addition of lysine had no detectable effect on growth. To further elucidate the lysine biosynthetic pathway in T. thermophilus, lysine auxotrophic mutants of T. thermophilus were obtained by chemical mutagenesis. For all lysine auxotrophic mutants, growth in a minimal medium was not restored by addition of diaminopimelic acid, whereas growth of two mutants was restored by addition of alpha-aminoadipic acid, a precursor of lysine in biosynthetic pathways of yeast and fungi. A BamHI fragment of 4.3

SUBMITTER: Kobashi N 

PROVIDER: S-EPMC93567 | biostudies-literature | 1999 Mar

REPOSITORIES: biostudies-literature