Family T5


Summary Holotypes Alignment Tree Genomes Structure Literature

Summary for family T5

Family type peptidaseT05.001 - ornithine acetyltransferase precursor (Saccharomyces cerevisiae), MEROPS Accession MER0011829 (peptidase unit: 215-441)
Content of familyPeptidase family T5 contains the self-processing ornithine acetyltransferase precursor.
History Identifier created: MEROPS 6.4 (24 September 2003)
Catalytic typeThreonine
Active site residuesT215 
Active siteMaturation of the precursor occurs through autoproteolysis of Ala214Thr215. The mature product produced is a 57kDa heterodimer with subunits of 31kDa and 26kDa. Mutation of the catalytic threonine renders the peptidase catalytically inactive (Abadjieva et al., 2000).
Activities and specificitiesThe region around the scissile bond of the precursor protein is highly conserved. In the type example for family T5 the sequence is KGAGMICPNMATLLG. The mutation of the threonine immediately C-terminal to the scissile bond to an alanine results in the accumulation of the uncleaved precursor (Abadjieva et al., 2000)
Molecular structureThe tertiary structure has been solved for the homologue from Streptomyces clavuligerus, and shows an alpha/beta/beta/alpha fold similar to that of other Ntn-hydrolases. However, differences in the connectivity imply a different structural fold derived from convergent evolution, and the only true structural homologue is the DmpA aminopeptidase (P01.001) (Elkins et al., 2005). Because of the structural relationship to members of family P1, T5 is included in the same clan, PE.
Distribution of family Bacteria details  
Archaea details  
Protozoa details  
Fungi -  
Plants details  
Animals details  
Viruses -  
Biological functionsOnly the precursor of ornithine acetyltransferase has peptidase activity. The mature form of the enzyme released by the autoproteolytic cleavage of the precursor catalyses the reversible interchange of an acetyl group between N-acetylornithine and glutamate (Liu et al., 1995)
Statistics for family T5Sequences:3822
Identifiers with PDB entries:2
Downloadable files Sequence library (FastA format)
Sequence alignment (FastA format)
Phylogenetic tree (Newick format)
Other databases INTERPRO IPR002813
PFAM PF01960
SCOP 111219
Peptidases and Homologues MEROPS ID Structure
ornithine acetyltransferase precursorT05.001-
ArgJ protein (archea)T05.002Yes
family T5 non-peptidase homologuesnon-peptidase homologue-
family T5 unassigned peptidasesunassignedYes