CLONING AND SEQUENCING OF THE SARCOSINE OXIDASE GENE FROM ARTHROBACTER SP TE1826

The gene encoding sarcosine oxidase from Arthrobacter sp. TE1826 (soxA) was cloned in Escherichia coli by a convenient plate assay. it was located within a 1.7-kbp PstI-EcoRI fragment of the recombinant plasmid pSAOEP3. The purified sarcosine oxidase from the recombinant strain was found to be the same as that from the parental strain. The DNA sequence of soxA was determined, and an open reading frame composed of 389 amino acid residues was found. By Edman degradation of the enzyme, it was revealed that the amino-terminal amino acid (methionine) was eliminated in the parental strain and E. coli. The molecular weight (43,249) of the enzyme was consistent with the result from SDS-polyacrylamide gel electrophoresis. The FAD-binding site was found in the amino-terminal region of sarcosine oxidase by a homology search. The soxA gene was subcloned on a shuttle vector, pHV300PLK, and was expressed in both E. coli and Bacillus subtilis in the absence of an inducer, although the enzyme was induced with sarcosine in the parental strain.