CLONING, NUCLEOTIDE-SEQUENCE, AND REGULATION OF THE BACILLUS-SUBTILIS GPR GENE, WHICH CODES FOR THE PROTEASE THAT INITIATES DEGRADATION OF SMALL, ACID-SOLUBLE PROTEINS DURING SPORE GERMINATION

The gpr gene, which codes for the protease that initiates degradation of small, acid-soluble proteins during spore germination, has been cloned from Bacillus megaterium and Bacillus megaterium and Bacillus subtilis, and its nucleotide sequence has been determined. Use of a translational gpr-lacZ fusion showed that the B. subtilis gpr gene was expressed primarily, if not exclusively, in the forespore compartment of the sporulating cell, with expression taking place approximately 1 h before expression of glucose dehydrogenase and ssp genes. gpr-lacZ expression was abolished in spoIIAC (sig F) and spoIIIE mutants but was reduced only approximately 50% in a spoIIIG (sigG) mutant. However, the kinetics of the initial approximately 50% of gpr-lacZ expression were unaltered in a spoIIIG mutant. The in vivo transcription start site of gpr has been identified and found to be identical to the in vitro start site on this gene with either E-sigma-F or E-sigma-G. Induction of sigma-G synthesis in vivo turned on gpr-lacZ expression in parallel with synthesis of glucose dehydrogenase. These data are consistent with gpr transcription during sporulation first by E-sigma-F and then by E-sigma-G.