Family U73


Summary Holotypes Alignment Tree Genomes Literature

Summary for family U73

Family type peptidaseU73.001 - small protease (Pseudomonas aeruginosa) (Pseudomonas aeruginosa), MEROPS Accession MER0492485 (peptidase unit: 24-191)
Content of family
History Identifier created: MEROPS 9.10 (20 December 2013)
The small protease from Pseudomonas aeruginosa has a molecular mass of only 18.5 kDa (Marquart et al., 2005), which makes it one of the smallest monomeric peptidases known. It is a secreted protein and has been shown to be a virulence factor in keratitis (Tang et al., 2013).
Catalytic typePeptidase of unknown catalytic type
Active siteInhibition by TLCK (Tang et al., 2009) suggests that the small protease is either a serine or cysteine peptidase, and absence of any Cys residues in the sequence suggests it is a serine peptidase. Residues that are conserved in the family and which might be active site residues are His43, His91, Ser94 and Asp96. His91, Ser94 and Asp96 are clustered at one end of the barrel opposite the flap, and His43 is on the flap.
Activities and specificitiesThe small protease has been shown to cleave type I and type IV collagen (Tang et al., 2009).
InhibitorsInhibition by TLCK has been reported (Tang et al., 2009).
Molecular structureThe tertiary structure has been determined for the YceI protein from Escherichia coli and the TT1927b protein from Thermus thermophilus (Handa et al., 2005), and both show a lipocalin-like fold consisting of a beta barrel with a flexible flap at one end of the barrel.
Distribution of family Bacteria details  
Archaea -  
Protozoa -  
Fungi -  
Plants details  
Animals details  
Viruses -  
Biological functionsWhen injected into rabbit eyes, the small protease causes inflammation and the peptidase is believed to be a virulence factor during keratitis, which is inflammation of the cornea of the eye (Tang et al., 2009).
Statistics for family U73Sequences:14
Identifiers with PDB entries:0
Downloadable files Sequence library (FastA format)
Sequence alignment (FastA format)
Phylogenetic tree (Newick format)
Peptidases and Homologues MEROPS ID Structure
small protease (Pseudomonas aeruginosa)U73.001-
family U73 unassigned peptidaseunassigned-