title: Protein secretion and surface display in Gram-positive bacteria.
abstract: The cell wall peptidoglycan of Gram-positive bacteria functions as a surface organelle for the transport and assembly of proteins that interact with the environment, in particular, the tissues of an infected host. Signal peptide-bearing precursor proteins are secreted across the plasma membrane of Gram-positive bacteria. Some precursors carry C-terminal sorting signals with unique sequence motifs that are cleaved by sortase enzymes and linked to the cell wall peptidoglycan of vegetative forms or spores. The sorting signals of pilin precursors are cleaved by pilus-specific sortases, which generate covalent bonds between proteins leading to the assembly of fimbrial structures. Other precursors harbour surface (S)-layer homology domains (SLH), which fold into a three-pronged spindle structure and bind secondary cell wall polysaccharides, thereby associating with the surface of specific Gram-positive microbes. Type VII secretion is a non-canonical secretion pathway for WXG100 family proteins in mycobacteria. Gram-positive bacteria also secrete WXG100 proteins and carry unique genes that either contribute to discrete steps in secretion or represent distinctive substrates for protein transport reactions.
authors.affiliation: Department of Microbiology, University of Chicago, 920 East 58th Street, Chicago, IL 60637, USA. oschnee@bsd.uchicago.edu
authors.forename: Olaf
authors.initials: O
authors.lastname: Schneewind
authors.forename: Dominique M
authors.initials: DM
authors.lastname: Missiakas
mesh_terms: D019881:Aminoacyltransferases / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry; D058947:Bacterial Secretion Systems; D002462:Cell Membrane / Q000737:chemistry; D002473:Cell Wall / Q000737:chemistry; D003546:Cysteine Endopeptidases / Q000737:chemistry; D010861:Fimbriae, Bacterial / Q000737:chemistry / Q000502:physiology; D005798:Genes, Bacterial; D006094:Gram-Positive Bacteria / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D010457:Peptidoglycan / Q000737:chemistry; D058105:Polymerization; D021382:Protein Sorting Signals; D017434:Protein Structure, Tertiary; D021381:Protein Transport
chemical_list: D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D010457:Peptidoglycan; D021382:Protein Sorting Signals; D019881:Aminoacyltransferases; C120542:sortase A; D003546:Cysteine Endopeptidases