Bacillus subtilis 168 Contains Two Differentially Regulated Genes Encoding l -Asparaginase

Abstract

ABSTRACT Expression of the two Bacillus subtilis genes encoding l -asparaginase is controlled by independent regulatory factors. The ansZ gene (formerly yccC ) was shown by mutational analysis to encode a functional l -asparaginase, the expression of which is activated during nitrogen-limited growth by the TnrA transcription factor. Gel mobility shift and DNase I footprinting experiments indicate that TnrA regulates ansZ expression by binding to a DNA site located upstream of the ansZ promoter. The expression of the ansA gene, which encodes the second l -asparaginase, was found to be induced by asparagine. The ansA repressor, AnsR, was shown to negatively regulate its own expression.