Yilmaz, Ebru I.Caydasi, Ayse K.Oezcengiz, Guelay2024-04-242024-04-2420081367-54351476-5535https://doi.org/10.1007/s10295-007-0259-8https://hdl.handle.net/11468/14603The aspartate pathway of Streptomyces clavuligerus is an important primary metabolic pathway which provides substrates for beta-lactam synthesis. In this study, the hom gene which encodes homoserine dehydrogenase was cloned from the cephamycin C producer S. clavuligerus NRRL 3585 and characterized. The fully sequenced open reading frame encodes 433 amino acids with a deduced M (r) of 44.9 kDa. The gene was heterologously expressed in the auxotroph mutant Escherichia coli CGSC 5075 and the recombinant protein was purified. The cloned gene was used to construct a plasmid containing a hom disruption cassette which was then transformed into S. clavuligerus. A hom mutant of S. clavuligerus was obtained by insertional inactivation via double crossover, and the effect of hom gene disruption on cephamycin C yield was investigated by comparing antibiotic levels in culture broths of this mutant and in the parental strain. Disruption of hom gene resulted in up to 4.3-fold and twofold increases in intracellular free L-lysine concentration and specific cephamycin C production, respectively, during stationary phase in chemically defined medium.eninfo:eu-repo/semantics/openAccessStreptomyces ClavuligerusHomoserine DehydrogenaseCephamycin CAspartate PathwayGene DisruptionArticle35117WOS:0002514873000012-s2.0-368490533551790987010.1007/s10295-007-0259-8Q1Q2