Transcription of genes near the sspE locus of the Bacillus subtilis genome

The yfhP, yfhQ (mutY homologue), yfhS and yfhR (oxidoreductase homologue) genes, which are located upstream of the sspE locus, have been identified in the Bacillus subtilis genome. Transcriptional analysis showed that yfhP, yfhQ and yfhR are transcribed during the exponential growth phase, and sspE is monocistronically transcribed in the late sporulation phase and co-transcribed with yfhQ and/or yfhR during exponential growth. However, SspE was not translated during this period. Northern blot and primer extension analyses indicated that yfhS is transcribed by E·E during sporulation. No significant difference between wild-type and yfhS mutant strains was found in the rate of sporulation or germination, the heat tolerance of spores or the transcription of the sspE locus during sporulation. The transcription of the yfhP and yfhQ-yfhR-sspE loci increased 2.5- and 5.3-fold in a yfhP-deficient strain compared to the wild-type strain at t -2 (2 h before initiation of sporulation). In addition, transcription corresponding to the yfhR-sspE loci increased more than twofold with maximum values observed at t -15. These results suggest that YfhP may act as a negative regulator for the transcription of yfhQ, yfhR, sspE and yfhP.