v5.1.0.3
Cicer data from the Legume Information System
Type | Domain |
Description | Proteolytic enzymes that exploit serine in their catalytic activity are ubiquitous, being found in viruses, bacteria and eukaryotes [ ]. They include a wide range of peptidase activity, including exopeptidase, endopeptidase, oligopeptidase and omega-peptidase activity. Many families of serine protease have been identified, these being grouped into clans on the basis of structural similarity and other functional evidence []. Structures are known for members of the clans and the structures indicate that some appear to be totally unrelated, suggesting different evolutionary origins for the serine peptidases [].Not withstanding their different evolutionary origins, there are similarities in the reaction mechanisms of several peptidases. Chymotrypsin, subtilisin and carboxypeptidase C have a catalytic triad of serine, aspartate and histidine in common: serine acts as a nucleophile, aspartate as an electrophile, and histidine as a base [ ]. The geometric orientations of the catalytic residues are similar between families, despite different protein folds []. The linear arrangements of the catalytic residues commonly reflect clan relationships. For example the catalytic triad in the chymotrypsin clan (PA) is ordered HDS, but is ordered DHS in the subtilisin clan (SB) and SDH in the carboxypeptidase clan (SC) [ , ].The alpha-lytic protease prodomain is associated with serine peptidases, specifically the alpha-lytic endopeptidases and streptogrisin A, B, C, D and E, which are bacterial enzymes and which belong to MEROPS peptidase subfamily S1A ( ). The protease precursor in Gram-negative bacterial proteases may be a general property of extracellular bacterial proteases [ ]. The proteases are encoded with a large (166 amino acid) N-terminal pro region that is required transiently both in vivoand in vitrofor the correct folding of the protease domain [ , ]. The pro region also acts as a potent inhibitor of the mature enzyme []. |
Short Name | Pept_S1_alpha_lytic |