The yfhP, yfhQ (mutY homologue), yfhS and yfhR (oxidoreductase homologue) g
enes, which are located upstream of the sspE locus, have been identified in
the Bacillus subtilis genome. Transcriptional analysis showed that yfhP, y
fhQ and yfhR are transcribed during the exponential growth phase, and sspE
is monocistronically transcribed in the late sporulation phase and co-trans
cribed with yfhQ and/or yfhR during exponential growth. However, SspE was n
ot translated during this period. Northern blot and primer extension analys
es indicated that yfhS is transcribed by E sigma(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 o
f the yfhP and yfhQ-yfhR-sspE loci increased 2.5- and 5.3-fold in a yfhP-de
ficient strain compared to the wild-type strain at t(-2) (2 h before initia
tion 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 yfhB yfhR, sspE and yfhP.