title: The type 4 prepilin peptidases comprise a novel family of aspartic acid proteases.
abstract: Type 4 prepilins or prepilin-like-proteins are secreted by a wide range of bacterial species and are required for a variety of functions including type 4 pilus formation, toxin and other enzyme secretion, gene transfer, and biofilm formation. A distinctive feature of these proteins is the presence of a specialized leader peptide that is cleaved off by a cognate membrane-bound type 4 prepilin peptidase (TFPP) during the process of secretion. In this report we show that the TFPPs represent a novel family of bilobed aspartate proteases that is unlike any other protease. The active site pairs of aspartic acids of the two TFPPs in Vibrio cholerae are found at positions 125 and 189 of TcpJ and 147 and 212 of VcpD. Corresponding aspartate residues are completely conserved throughout this extensive peptidase family.
authors.affiliation: Department of Microbiology, Dartmouth Medical School, Hanover, New Hampshire 03755, USA.
authors.forename: C F
authors.initials: CF
authors.lastname: LaPointe
authors.forename: R K
authors.initials: RK
authors.lastname: Taylor
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D003001:Cloning, Molecular; D017124:Conserved Sequence; D010450:Endopeptidases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli; D005816:Genetic Complementation Test; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes; D016297:Mutagenesis, Site-Directed; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D014734:Vibrio cholerae / Q000201:enzymology / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D009097:Multienzyme Complexes; D011994:Recombinant Proteins; D010450:Endopeptidases; C092637:Tcpj protein, Vibrio cholerae; C074273:type IV prepilin peptidase