Family C102


Summary Holotypes Genomes Structure Literature

Summary for family C102

Family type peptidaseC102.001 - GtgE peptidase (Salmonella enterica), MEROPS Accession MER0400815 (peptidase unit: 1-228)
Content of family
History Identifier created: MEROPS 9.11 (21 July 2014)
Many pathogenic bacteria use a type III secretion system to deliver proteins into the host cell where they act as effectors able to reprogram host defences and aid pathogenesis. The gtgE gene has been shown to be essential for virulence of the bacterium Salmonella enterica serovar Typhimurium carrying the Gifsy-2 temperate bacteriophage (Ho et al., 2002). The GtgE protein is a type III secretion protein which is a peptidase able to cleave GTPases (Spano et al., 2011; Kohler et al., 2014). These GTPases act in conjunction with BLOC proteins to deliver proteins to lysosome-like organelles. By cleaving the GTPases, transport of antimicrobial factors to the Salmonella containing vesicle is prevented, allowing the pathogen to survive (Kohler et al., 2014).
Catalytic typeCysteine
Active siteThe catalytic triad residues Cys, His and Asp were identified by site-directed mutagenesis (Spano et al., 2011, Kohler et al., 2014).
Activities and specificitiesThe GtgE peptidase has been shown to cleave GTPases Rab29, Rab32 and Rab38; Rab29 is cleaved at a Gly+Val bond (Spano et al., 2011).
InhibitorsInhibition with N-ethylmaleimide, antipain and chymostatin has been shown (Kohler et al., 2014).
Molecular structureThe tertiary structure of an N-terminally truncated fragment of the GtgE peptidase has been solved (Kohler et al., 2014). The structure is similar to that of peptidases in family C1, hence family C102 is included in the same clan, CA.
Distribution of family Bacteria details  
Archaea -  
Protozoa -  
Fungi -  
Plants -  
Animals -  
Viruses -  
Biological functionsThe GtgE peptidase is a component of the Salmonella enterica type III secretion system and is a peptidase able to inactivate certain GTPases, thus preventing delivery of antimicrobial agents to the vesicle containing the bacterium, and thus prolonging its life (Spano et al., 2011).
Pharmaceutical and biotech relevanceWhereas serovar Typhimurium can infect multiple hosts, Salmonella enterica serovar Typhi, the causative agent for typhoid fever, is unusually restricted to humans. Normally, serovar Typhi lacks the gtgE] gene, but if genetically engineered to express gtgE then the bacterium can survive in mouse macrophages (Spano & Galan, 2012).
Statistics for family C102Sequences:1
Identifiers with PDB entries:1
Downloadable files Sequence library (FastA format)
Peptidases and Homologues MEROPS ID Structure
GtgE peptidaseC102.001Yes