Family M85


Summary Holotypes Alignment Tree Genomes Structure Literature

Summary for family M85

Family type peptidaseM85.001 - NleC peptidase (Escherichia coli) (Escherichia coli), MEROPS Accession MER0195406 (peptidase unit: 21-285)
Content of familyPeptidase family M85 contains endopeptidases.
History Identifier created: MEROPS 9.4 (31 January 2011)
Pathogenic bacteria can manipulate host cells by affecting cell signalling pathways. Enteropathogenic and enterohemorrhagic Escherichia coli inject virulence factors into host cell by means of a needle-like protein complex called the type three secretion system. The proteins NleC and NleE, injected in this way, are two factors that down-regulate the NFkappaB signalling pathway. NleC has been shown to be a metallopeptidase that cleaves the p65 subunit of NF-kappaB, disrupting activation and inhibiting the inflammation response in the host (Yen et al., 2010).
Catalytic typeMetallo
Active site residuesH183 E184 H187 D194 Y227 
Active siteThere is a conserved HEXXH motif, which in metallopeptidase from clan MA has been shown to be metal-binding. The histidines are zinc ligands and the glutamate an active site residue. In NleC, site-directed mutagenesis of the second histidine prevented cleavage of p65 (Yen et al., 2010).
Activities and specificitiesThe p65 subunit of NF-kappaB is cleaved, but cleavage positions have not been identified.
InhibitorsEDTA (10 mM) prevented cleavage of p65 (Yen et al., 2010).
Molecular structureNo tertiary structure has been solved and family M85 is included in clan MA because of the presence of the HEXXH metal-binding motif.
Distribution of family Bacteria details  
Archaea -  
Protozoa -  
Fungi -  
Plants -  
Animals -  
Viruses -  
Biological functionsThe NleC and NleE proteins act co-operatively to reduce or eliminate the inflammatory response of the host during Escherichia coli infection (Yen et al., 2010).
Statistics for family M85Sequences:12
Identifiers with PDB entries:1
Downloadable files Sequence library (FastA format)
Sequence alignment (FastA format)
Phylogenetic tree (Newick format)
Peptidases and Homologues MEROPS ID Structure
NleC peptidase (Escherichia coli)M85.001Yes
family M85 unassigned peptidasesunassigned-