Isolation and analysis of the argG gene encoding argininosuccinate synthetase from Corynebacterium glutamicum

Abstract

The argG gene of Corynebacterium glutamicum encoding argininosuccinate synthetase (EC6345) was cloned and sequenced. The gene was cloned by heterologous complementation of an Escherichia coli arginine auxotrophic mutant (argG(-)). The cloned DNA fragment also. complements E. coli argD, argF, and argH mutants, suggesting a clustered organization of the genes in the chromosome. The coding region-of the argG gene is 1,206 nucleotides long with a deduced molecular weight of about 44 kDa, comparable with the predicted size of the expressed protein on. the SDS-PAGE. Computer analysis revealed that the amino acid sequence of the argG gene product had a high similarity to that of Mycobacterium tuberculosis and Streptomyces clavuligerus. Two conserved sequence motifs within the ArgG appear to be ATP-binding sites which correspond to 2 of the 3 conserved regions found in sequences of all known argininosuccinate synthetases.