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Protein Domain : IPR000668

Name  Peptidase C1A, papain C-terminal Short Name  Peptidase_C1A_C
Type  Domain Description  In the MEROPS database peptidases and peptidase homologues are grouped into clans and families. Clans are groups of families for which there is evidence of common ancestry based on a common structural fold:Each clan is identified with two letters, the first representing the catalytic type of the families included in the clan (with the letter 'P' being used for a clan containing families of more than one of the catalytic types serine, threonine and cysteine). Some families cannot yet be assigned to clans, and when a formal assignment is required, such a family is described as belonging to clan A-, C-, M-, N-, S-, T- or U-, according to the catalytic type. Some clans are divided into subclans because there is evidence of a very ancient divergence within the clan, for example MA(E), the gluzincins, and MA(M), the metzincins.Peptidase families are grouped by their catalytic type, the first character representing the catalytic type: A, aspartic; C, cysteine; G, glutamic acid; M, metallo; N, asparagine; S, serine; T, threonine; and U, unknown. The serine, threonine and cysteine peptidases utilise the amino acid as a nucleophile and form an acyl intermediate - these peptidases can also readily act as transferases. In the case of aspartic, glutamic and metallopeptidases, the nucleophile is an activated water molecule. In the case of the asparagine endopeptidases, the nucleophile is asparagine and all are self-processing endopeptidases. In many instances the structural protein fold that characterises the clan or family may have lost its catalytic activity, yet retain its function in protein recognition and binding. Cysteine peptidases have characteristic molecular topologies, which can be seen not only in their three-dimensional structures, but commonly also in the two-dimensional structures. These are peptidases in which the nucleophile is the sulphydryl group of a cysteine residue. Cysteine proteases are divided into clans (proteins which are evolutionary related), and further sub-divided into families, on the basis of the architecture of their catalytic dyad or triad []. This group of proteins belong to the peptidase family C1, sub-family C1A (papain family, clan CA). It includes proteins classed as non-peptidase homologues. These are have either been shown experimentally to lack peptidase activity or lack one or more of the active site residues. The papain family has a wide variety of activities, including broad-range (papain) and narrow-range endo-peptidases, aminopeptidases, dipeptidyl peptidases and enzymes with both exo- and endo-peptidase activity []. Members of the papain family are widespread, found in baculovirus [], eubacteria, yeast, and practically all protozoa, plants and mammals []. The proteins are typicallylysosomal or secreted, and proteolytic cleavage of the propeptide is required for enzyme activation, although bleomycin hydrolase is cytosolic in fungi and mammals []. Papain-like cysteine proteinases are essentially synthesised as inactive proenzymes (zymogens) with N-terminal propeptide regions. The activation process of these enzymes includes the removal of propeptide regions. The propeptide regions serve a variety of functions in vivo and in vitro. The pro-region is required for the proper folding of the newly synthesised enzyme, the inactivation of the peptidase domain and stabilisation of the enzyme against denaturing at neutral to alkaline pH conditions. Amino acid residues within the pro-region mediate their membrane association, and play a role in the transport of the proenzyme to lysosomes. Among the most notable features of propeptides is their ability to inhibit the activity of their cognate enzymes and that certain propeptides exhibit high selectivity for inhibition of the peptidases from which they originate [].The catalytic residues of papain are Cys-25 and His-159, other important residues being Gln-19, which helps form the 'oxyanion hole', and Asn-175, which orientates the imidazole ring of His-159.

Publication Counts Displayer

0 Child Features

0 Contains

3 Cross References

Identifier
Source . Name

Subject . Primary Identifier
PF00112 PFAM IPR000668
PR00705 PRINTS IPR000668
SM00645 SMART IPR000668

3 Data Sets

Name URL
TrEMBL data set http://www.ebi.ac.uk/trembl/
InterPro data set  
InterPro GO Annotation data set  

4 Found In

DB identifier Name Short Name Type
IPR013128 Peptidase C1A Peptidase_C1A Family
IPR015643 Peptidase C1A, cathepsin B Peptidase_C1A_cathepsin-B Family
IPR015645 Peptidase C1A, placentally-expressed cathepsin Pept_C1A_placental-cathepsin Family
IPR015644 Peptidase C1A, cathepsin K Peptidase_C1A_cathepsin-K Family

2 GO Annotation


Subject . Secondary Identifier

Subject . Name

Subject . Symbol

Ontology Term . Identifier

Ontology Term . Name
Peptidase C1A, papain C-terminal   GO:0008234 cysteine-type peptidase activity
Peptidase C1A, papain C-terminal   GO:0006508 proteolysis

2 Ontology Annotations


Subject . Secondary Identifier

Subject . Name

Subject . Symbol

Ontology Term . Identifier

Ontology Term . Name
Peptidase C1A, papain C-terminal   GO:0008234 cysteine-type peptidase activity
Peptidase C1A, papain C-terminal   GO:0006508 proteolysis

0 Parent Features

245 Proteins

DB identifier Primary Accession
Organism . Name
FBpp0086719 Q95029 Drosophila melanogaster
FBpp0086763 Q7K0S6 Drosophila melanogaster
FBpp0079644 Q9VKY4 Drosophila melanogaster
FBpp0075508 Q9V3U6 Drosophila melanogaster
FBpp0078272 Q9VNK6 Drosophila melanogaster
FBpp0086772 Q7JYA0 Drosophila melanogaster
FBpp0078465 Q9VN93 Drosophila melanogaster
FBpp0078464 H5V8F3 Drosophila melanogaster
FBpp0086091 A1ZAU4 Drosophila melanogaster
FBpp0086090 Q7K5N8 Drosophila melanogaster
FBpp0073669 Q9VY87 Drosophila melanogaster
FBpp0071697 Q7JWQ7 Drosophila melanogaster
FBpp0278474 Q28XS2 Drosophila pseudoobscura
FBpp0275168 Q2M011 Drosophila pseudoobscura
FBpp0274400 B5DPR9 Drosophila pseudoobscura
FBpp0274603 B5DQQ6 Drosophila pseudoobscura
FBpp0277631 Q291G0 Drosophila pseudoobscura
FBpp0278438 Q28XY3 Drosophila pseudoobscura
FBpp0284278 Q29HU8 Drosophila pseudoobscura
FBpp0300603 I5APD1 Drosophila pseudoobscura
FBpp0284455 B5DY59 Drosophila pseudoobscura
FBpp0278526 Q28XK9 Drosophila pseudoobscura
FBpp0276104 B5E0E4 Drosophila pseudoobscura
FBpp0306123 N6VFP6 Drosophila pseudoobscura
FBpp0159433 B4KCM1 Drosophila mojavensis
FBpp0160846 B4L169 Drosophila mojavensis
FBpp0160847 B4L168 Drosophila mojavensis
FBpp0162893 B4L162 Drosophila mojavensis
FBpp0163320 B4L7D4 Drosophila mojavensis
FBpp0164720 B4L388 Drosophila mojavensis