The omptin family of enterobacterial surface proteases/adhesins: from housekeeping in Escherichia coli to systemic spread of Yersinia pestis.
The omptins are a family of enterobacterial surface proteases/adhesins that share high sequence identity and a conserved beta-barrel fold in the outer membrane. The omptins are multifunctional, and the individual omptins exhibit differing virulence-associated functions. The Pla plasminogen activator of Yersinia pestis contributes by several mechanisms to bacterial invasiveness and the systemic, uncontrolled proteolysis in plague. Pla proteolytically activates the human proenzyme plasminogen and inactivates the antiprotease alpha2-antiplasmin, and its binding to laminin localizes the uncontrolled plasmin activity onto basement membranes. These properties enhance bacterial migration through tissue barriers. Pla also degrades circulating complement proteins and functions in bacterial invasion into human epithelial cells. PgtE of Salmonella enterica and OmpT of Escherichia coli have been shown to degrade cationic antimicrobial peptides from epithelial cells or macrophages. PgtE and SopA of Shigella flexneri appear important in the intracellular phases of salmonellosis and shigellosis, whereas functions of OmpT have mainly been associated with protein degradation in E. coli cells. The differing virulence roles and functions have been attributed to minor sequence variations at the surface-exposed regions important for substrate recognition, to the dependence of omptin functions on lipopolysaccharide, and to the different regulation of omptin expression.
General Microbiology, Faculty of Biosciences, University of Helsinki, P.O. Box 56 (Viikinkaari 9), FIN-00014 Helsinki, Finland.
Maini
M
Kukkonen
Timo K
TK
Korhonen
D018829:Adhesins, Bacterial / Q000235:genetics / Q000378:metabolism*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D005075:Biological Evolution; D010450:Endopeptidases / Q000235:genetics / Q000502:physiology; D004926:Escherichia coli / Q000472:pathogenicity / Q000502:physiology*; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D010447:Peptide Hydrolases; D010960:Plasminogen Activators / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D018272:Porins / Q000235:genetics / Q000502:physiology; D019779:Salmonella enterica / Q000472:pathogenicity / Q000502:physiology*; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D012763:Shigella flexneri / Q000472:pathogenicity / Q000502:physiology*; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism; D015010:Yersinia pestis / Q000472:pathogenicity / Q000502:physiology*
D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D018272:Porins; D037521:Virulence Factors; C499588:ompT protein, E coli; D010450:Endopeptidases; D010447:Peptide Hydrolases; C411337:PgtE protein, Salmonella enterica; C060971:SopA protein, Bacteria; C078140:Pla protease, Yersinia pestis; D010960:Plasminogen Activators; D012697:Serine Endopeptidases; C057840:omptin outer membrane protease