Abstract

Dihydrodipicolinate synthase (DHDPS) catalyses the first enzymatic step in the lysine-biosynthetic pathway in bacteria, plants and some fungi. In this study, cloning and submission of 3639 bp from Streptomyces rimosus NRRL 2455 to the EMBL database under the accession code EU617017 were carried out. The entiredprA gene was cloned and heterologously expressed in Escherichia coli BL21 (DE3) and the gene product was purified and analysed spectrophotometrically. AdprA^- knock-out mutant was created and showed a reduction of mycelia growth and spore formation by about 43 and 37%, respectively, as compared to the wild strain. Fed with meso-diaminopimelic acid, the dprA^- mutant regained its capability of mycelial growth, however no significant effect on spore formation was observed confirming that dprA gene product was involved in the biosynthesis of dihydrodipicolinate in S. rimosus NRRL 2455. This is the first report about identification of dihydrodipicolinate synthase of the order streptomycetes.

Key words: Dihydrodipicolinate synthase, lysine biosynthesis, Streptomyces rimosus NRRL 2455, dprA knock-out mutants