title: ComC is required for the processing and translocation of comGC, a pilin-like competence protein of Bacillus subtilis.
abstract: ComGC is a cell surface-localized protein required for DNA binding during transformation in Bacillus subtilis. It resembles type IV prepilins in its N-terminal domain, particularly in the amino acid sequence surrounding the processing cleavage sites of these proteins. ComC is another protein required for DNA binding, which resembles the processing proteases that cleave type IV prepilins. We show here that ComGC is processed in competent cells and that this processing requires ComC. We also demonstrate that the PilD protein of Neisseria gonorrhoeae, a ComC homologue, can process ComGC in Escherichia coli, and that the ComC protein itself is the only B. subtilis protein needed to accomplish cleavage of ComGC in the latter organism. Based on NaOH-solubility studies, we have shown that in the absence of ComC, but in the presence of all other competence proteins, B. subtilis is incapable of correctly translocating ComGC to the outer face of the cell membrane. Finally, we show that ComGC can be cross-linked to yield a form with higher molecular mass, possibly a dimer, and present evidence suggesting that formation of the higher mass complex takes place in the membrane, prior to translocation. Formation of this complex does not require ComC or any of the comG products, other than ComGC itself.
authors.affiliation: Public Health Research Institute, New York, New York 10016, USA.
authors.forename: Y S
authors.initials: YS
authors.lastname: Chung
authors.forename: D
authors.initials: D
authors.lastname: Dubnau
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism* / Q000502:physiology*; D001692:Biological Transport; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000502:physiology*; D010450:Endopeptidases; D004926:Escherichia coli / Q000378:metabolism; D005816:Genetic Complementation Test; D006863:Hydrogen-Ion Concentration; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000502:physiology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009097:Multienzyme Complexes; D009154:Mutation; D009344:Neisseria gonorrhoeae / Q000378:metabolism; D011487:Protein Conformation; D011498:Protein Precursors / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012995:Solubility; D013388:Succinimides / Q000494:pharmacology; D014169:Transformation, Bacterial
chemical_list: D001426:Bacterial Proteins; D003432:Cross-Linking Reagents; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D008565:Membrane Proteins; D009097:Multienzyme Complexes; D011498:Protein Precursors; D013388:Succinimides; C072854:bis(sulfosuccinimidyl)tartrate; C061650:comC protein, Bacillus subtilis; D010450:Endopeptidases; C067127:prepilin peptidase protein, Bacteria