LIS - Legume Information System
Information about legume traits for crop improvement
CicerMine
v5.1.0.3
Cicer data from the Legume Information System
v5.1.0.3
Cicer data from the Legume Information System
| Type | Family |
| Description | This entry represents the MEROPS peptidase subfamily M20A (clan MH), which includes human N-fatty-acyl-amino acid synthase/hydrolase PM20D1, Carboxypeptidase S from Saccharomyces cerevisiae and similar eukaryotic and bacterial sequences. PM20D1 is a secreted enzyme that regulates the endogenous N-fatty acyl amino acid (NAAs) tissue and circulating levels by functioning as a bidirectional NAA synthase/hydrolase [ ]. Carboxypeptidase S, which is used for certain peptides as sole nitrogen source, has a preference for releasing an amino acid attached to Gly []. The peptidases of this protein family have two catalytic zinc ions at the active site, bound by His/Asp, Asp, Glu, Asp/Glu and His. The catalysed reaction involves the release of an N-terminal amino acid, usually neutral or hydrophobic, from a polypeptide []. Over 70 metallopeptidase families have been identified to date. In these enzymes a divalent cation which is usually zinc, but may be cobalt, manganese or copper, activates the water molecule. The metal ion is held in place by amino acid ligands, usually three in number. In some families of co-catalytic metallopeptidases, two metal ions are observed in crystal structures ligated by five amino acids, with one amino acid ligating both metal ions. The known metal ligands are His, Glu, Asp or Lys. At least one other residue is required for catalysis, which may play an electrophillic role. Many metalloproteases contain an HEXXH motif, which has been shown in crystallographic studies to form part of the metal-binding site []. The HEXXH motif is relatively common, but can be more stringently defined for metalloproteases as 'abXHEbbHbc', where 'a' is most often valine or threonine and forms part of the S1' subsite in thermolysin and neprilysin, 'b' is an uncharged residue, and 'c' a hydrophobic residue. Proline is never found in this site, possibly because it would break the helical structure adopted by this motif in metalloproteases []. |
| Short Name | Pept_M20A |
