An alpha/beta-type, small, acid-soluble spore protein which has very high affinity for DNA prevents outgrowth of Bacillus subtilis spores

A derivative of SspC, a minor alpha/beta -type, small, acid-soluble spore p rotein (SASP) from Bacillus subtilis, was generated that has a very high af finity for DNA. This protein (SspC(Delta 11-D13K)) was able to confer UV re sistance on spores lacking alpha/beta -type SASP, and spores with SspC(Delt a 11-D13K) triggered germination normally. However, SspC(Delta 11-D13K) blo cked outgrowth of greater than or equal to 90% of germinated spores, and Ss pC(Delta 11-D13K) persisted in these germinated spores, whereas wild-type S spC was almost completely degraded. The outgrowth phenotype of spores with SspC(Delta 11-D13K) is proposed to be due to the high stability of the SspC (Delta 11-D13K)-DNA complex, which prevents rapid degradation of this alpha /beta -type SASP early in germination. The persistence of this protein on s pore DNA then interferes with transcription during spore outgrowth.