Family U49


Summary Holotypes Alignment Tree Genomes Literature

Summary for family U49

NamePeptidase family U49 (Lit protease family)
Family type peptidaseU49.001 - Lit peptidase (Escherichia coli), MEROPS Accession MER0004305 (peptidase unit: 1-297)
Content of familyPeptidase family U49 contains only the Lit peptidase from Escherischia coli.
History Identifier created: MEROPS 5.61 (29 October 2001)
Lit peptidase has been reviewed by Copeland & Kleanthous, 2004.
Catalytic typePeptidase of unknown catalytic type
Active siteNo active site residues have been identified in the Lit peptidase, although it may be significant that an HEXXH motif occurs in the sequence at residues 160 - 164 (see the Alignment).
Activities and specificitiesLit peptidase cleaves domain I of elongation factor Tu (Copeland & Kleanthous, 2004).
InhibitorsLit peptidase activity is not affected by the addition of zinc, and the zinc chelator 1,10-phenanthroline does not inhibit, as would have been expected for a metallopeptidase (Georgiou, 1998).
Molecular structureLit peptidase is a 33-kDa protein that contains two putative transmembrane domains, the second of which includes an HEXXH motif similar to the zinc-binding motif found in the metallopeptidases of clans MA and MM (Snyder, 1995). The peptidase is approximately 36% alpha helix and 31% beta-sheet (Copeland & Kleanthous, 2004).
Basis of clan assignmentProtein fold and active site residues are not known for any members of this family.
Distribution of family Bacteria details  
Archaea -  
Protozoa -  
Fungi -  
Plants -  
Animals -  
Viruses -  
Biological functionsLit peptidase has an important role in bacterial cell death in response to infection by bacteriophage T4. Following binding of Gol peptide to domains II and III of elongation factor Tu, the protease cleaves domain I of the elongation factor. This prevents binding of guanine nucleotides, shuts down translation and leads to cell death (Copeland & Kleanthous, 2004).The Lit-mediated proteolysis of EF-Tu alone appears to be sufficient to prevent the formation of active phage particles (Yu & Snyder, 1994) and thus to prevent further transmission of the phage.
Statistics for family U49Sequences:10
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
Lit peptidaseU49.001-
family U49 unassigned peptidasesunassigned-