Expression and purification of 30 kilodalton protein antigen of Ara- Burkholderia pseudomallei.

The 30 kDa protein of B. pseudomallei is found in virulent Ara- but not avirulent Ara+ strain. The gene was cloned in Escherichia coli JM105 employing pInIII-C2 vector. The open reading frame was 870 nucleotides with a guanine plus cytosine content of 69.9%. Arginine was the most abundant amino acid in the protein, having a PI of 12.65. Nucleotide sequence of the gene was 96% identical to B. pseudomallei 1710b chromosome II sequence CP000125.1, encoding an oxidoreductase of the short chain dehydrogenase/reductase family. The 30 kDa antigen was expressed as a maltose-fusion protein with a yield of 5.25 mg/l of bacterial culture.