TEMPERATURE-SENSITIVE SPORULATION CAUSED BY A MUTATION IN THE BACILLUS-SUBTILIS SECY GENE

A thermosensitive sporulation mutant of Bacillus subtilis containing a mutation in the secY gene was isolated and characterized. No asymmetr ic septum specific to the sporulation was detected by electron microsc opy at the noupermissive temperature, indicating that the block occurr ed at a very early stage of sporulation. Furthermore, competence devel opment in the mutant cell was affected even at the sporulation-profici ent temperature. It is assumed that the SecY protein of B. subtilis ha s multiple roles both in the regulation of spore formation and in stat ionary-phase-associated phenomena.