An α/β-Type, Small, Acid-Soluble Spore Protein Which Has Very High Affinity for DNA Prevents Outgrowth ofBacillus subtilis Spores

摘要

A derivative of SspC, a minor α/β-type, small, acid-soluble spore protein (SASP) from Bacillus subtilis, was generated that has a very high affinity for DNA. This protein (SspCΔ11-D13K) was able to confer UV resistance on spores lacking α/β-type SASP, and spores with SspCΔ11-D13Ktriggered germination normally. However, SspCΔ11-D13Kblocked outgrowth of ≥90% of germinated spores, and SspCΔ11-D13K persisted in these germinated spores, whereas wild-type SspC was almost completely degraded. The outgrowth phenotype of spores with SspCΔ11-D13K is proposed to be due to the high stability of the SspCΔ11-D13K-DNA complex, which prevents rapid degradation of this α/β-type SASP early in germination. The persistence of this protein on spore DNA then interferes with transcription during spore outgrowth.