This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Sanchez-Salas, J L Articles by Setlow, P Search for Related Content PubMed PubMed Citation Articles by Sanchez-Salas, J L Articles by Setlow, P

research-article

Proteolytic processing of the protease which initiates degradation of small, acid-soluble proteins during germination of Bacillus subtilis spores.

Department of Biochemistry, University of Connecticut Health Center, Farmington 06030-3305.

ABSTRACT

Degradation of small, acid-soluble spore proteins during germination of Bacillus subtilis spores is initiated by a sequence-specific protease called GPR. Western blot (immunoblot) analysis of either Bacillus megaterium or B. subtilis GPR expressed in B. subtilis showed that GPR is synthesized at about the third hour of sporulation in a precursor form and is processed to an approximately 2- to 5-kDa-smaller species 2 to 3 h later, at or slightly before the time of accumulation of dipicolinic acid by the forespore. This was found with both normal levels of expression of B. subtilis and B. megaterium GPR in B. subtilis, as well as when either protein was overexpressed up to 100-fold. The sporulation-specific processing of GPR was blocked in all spoIII, -IV, and -V mutants tested (none of which accumulated dipicolinic acid), but not in a spoVI mutant which accumulated dipicolinic acid. The amino-terminal sequences of the B. megaterium and B. subtilis GPR initially synthesized in sporulation were identical to those predicted from the coding genes' sequences. However, the processed form generated in sporulation lacked 15 (B. megaterium) or 16 (B. subtilis) amino-terminal residues. The amino acid sequence surrounding this proteolytic cleavage site was very homologous to the consensus sequence recognized and cleaved by GPR in its small, acid-soluble spore protein substrates. This observation, plus the efficient processing of overproduced GPR during sporulation, suggests that the GPR precursor may autoproteolyze itself during sporulation. During spore germination, the GPR from either species expressed in B. subtilis was further processed by removal of one additional amino-terminal amino acid (leucine), generating the mature protease which acts during spore germination.

This article has been cited by other articles:

• Paredes-Sabja, D., Setlow, B., Setlow, P., Sarker, M. R. (2008). Characterization of Clostridium perfringens Spores That Lack SpoVA Proteins and Dipicolinic Acid. J. Bacteriol. 190: 4648-4659 [Abstract] [Full Text]  
• Carroll, T. M., Setlow, P. (2005). Site-Directed Mutagenesis and Structural Studies Suggest that the Germination Protease, GPR, in Spores of Bacillus Species Is an Atypical Aspartic Acid Protease. J. Bacteriol. 187: 7119-7125 [Abstract] [Full Text]  
• Shimamoto, S., Moriyama, R., Sugimoto, K., Miyata, S., Makino, S. (2001). Partial Characterization of an Enzyme Fraction with Protease Activity Which Converts the Spore Peptidoglycan Hydrolase (SleC) Precursor to an Active Enzyme during Germination of Clostridium perfringens S40 Spores and Analysis of a Gene Cluster Involved in the Activity. J. Bacteriol. 183: 3742-3751 [Abstract] [Full Text]  
• Paidhungat, M., Setlow, B., Driks, A., Setlow, P. (2000). Characterization of Spores of Bacillus subtilis Which Lack Dipicolinic Acid. J. Bacteriol. 182: 5505-5512 [Abstract] [Full Text]  
• Nessi, C., Jedrzejas, M. J., Setlow, P. (1998). Structure and Mechanism of Action of the Protease That Degrades Small, Acid-Soluble Spore Proteins during Germination of Spores of Bacillus Species. J. Bacteriol. 180: 5077-5084 [Abstract] [Full Text]