Cloning, sequence and expression of the argG gene from Streptomyces lavendulae

The argG gene, encoding argininosuccinate synthetase, was cloned from Streptomyces lavendulae KCCS0055 by colony hybridization using the argG-carrying 2.1-kb fragment of S. coelicolor DNA as a probe. The restriction map of the cloned DNA fragment was very similar to that of S. coelicolor. This DNA fragment could complement the argG mutation of both S. lividans 1326 I10 and Escherichia coli K-12 JE5694, suggesting that the fragment contained a promoter for both E. coli and S. lividans. The subcloning experiment using E. coli K-12 JE5694 as a host has indicated that the essential region for argG is contained in the 2.5-kb DNA fragment. The translational product was identified as a 56-kDa kDa protein in minicells and by conventional gel electrophoresis. Determination of the nucleotide (nt) sequence of the 2.5-kb DNA fragment revealed one open reading frame of 1449 bp. The amino acid (aa) sequence analysis showed that the N-terminus was Ser, and 9 aa from the N terminus were completely identical with those deduced from the nt sequence. Nuclease S1 mapping indicated that the transcription start point is located near the start codon.