Summary: Porcine arterivirus-type cysteine proteinase alpha
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Porcine arterivirus-type cysteine proteinase alpha Provide feedback
Corresponds to Merops family C31. These peptidases are involved in viral polyprotein processing in replication.
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This tab holds annotation information from the InterPro database.
InterPro entry IPR008741
Arteriviruses are enveloped, positive-stranded RNA viruses and include pathogens of major economic concern to the swine- and horse-breeding industries:
- Equine arteritis virus (EAV).
- Porcine reproductive and respiratory syndrome virus (PRRSV).
- Mice actate dehydrogenase-elevating virus.
- Simian hemorrhagic fever virus.
The arterivirus replicase gene is composed of two open reading frames (ORFs). ORF1a is translated directly from the genomic RNA, whereas ORF1b can be expressed only by ribosomal frameshifting, yelding a 1ab fusion protein. Both replicase gene products are multidomain precursor proteins which are proteolytically processed into functional nonstructural proteins (nsps) by a complex proteolytic cascade that is directed by four (PRRSV/LDV) or three (EAV) proteinase domains encoded in ORF1a. The arterivirus replicase processing scheme involves the rapid autoproteolytic release of two or three N-terminal nsps (nsp1 (or nsp1alpha/1beta) and nsp2) and the subsequent processing of the remaining polyproteins by the "main protease" residing in nsp4, together resulting in a set of 13 or 14 individual nsps.
The arterivirus nsp1 region contains a tandem of papain-like cysteine autoprotease domains (PCPalpha and PCPbeta), but in EAV PCPalpha has lost its enzymatic activity, resulting in the 'merge' of nsp1alpha and nsp1beta into a single nsp1 subunit. Thus, instead of three self-cleaving N-terminal subunits, EAV has two: nsp1 and nsp2. The PCPalpha and PCPbeta domains mediate the nsp1alpha|1beta and nsp1beta|2 cleavages, respectively. The catalytic dyad of PCPalpha and PCPbeta domains is composed of Cys and His residues. In EAV, a Lys residue is found in place of the catalytic Cys residue, which explains the proteolytic deficiency of the EAV PCPalpha domain [PUBMED:7769711, PUBMED:10725411, PUBMED:11172046, PUBMED:20696193]. The PCPalpha and PCPbeta domains form respectively MEROPS peptidase families C31 and C32.
The PCPalpha and PCPbeta domains have a typical papain fold, which consists of a compact global region containing sequentially connected left (L) and right (R) parts in a so-called standard orientation. The L subdomain of PCPalpha consists of four alpha-helices, while the R subdomain is formed by three antiparallel beta strands [PUBMED:19706710]. The L subdomain of the PCBbeta consists of three alpha-helices, while the R subdomain is formed by four antiparallel beta-strands [PUBMED:20410261]. The Cys and His residues face each other at the L-R interface and form the catalytic centre of the PCPalpha and PCPbeta domains [PUBMED:19706710, PUBMED:20410261].
This entry represents the PCPalpha domain (peptidase C31).
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
|Molecular function||cysteine-type endopeptidase activity (GO:0004197)|
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This clan includes peptidases with the papain-like fold.
The clan contains the following 60 members:Acetyltransf_2 Amidase_5 Amidase_6 CHAP DUF1175 DUF1287 DUF1460 DUF2272 DUF3335 DUF553 DUF830 EDR1 Guanylate_cyc_2 LRAT NLPC_P60 OTU Peptidase_C1 Peptidase_C10 Peptidase_C12 Peptidase_C16 Peptidase_C1_2 Peptidase_C2 Peptidase_C21 Peptidase_C23 Peptidase_C27 Peptidase_C28 Peptidase_C31 Peptidase_C32 Peptidase_C33 Peptidase_C34 Peptidase_C36 Peptidase_C39 Peptidase_C39_2 Peptidase_C42 Peptidase_C47 Peptidase_C48 Peptidase_C5 Peptidase_C54 Peptidase_C58 Peptidase_C6 Peptidase_C65 Peptidase_C7 Peptidase_C70 Peptidase_C71 Peptidase_C78 Peptidase_C8 Peptidase_C9 Peptidase_C93 Peptidase_C98 Phytochelatin Rad4 Transglut_core Transglut_core2 Transglut_core3 Transglut_i_TM Transpep_BrtH UCH UCH_1 Viral_protease YopJ
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Curation and family details
|Number in seed:||3|
|Number in full:||229|
|Average length of the domain:||105.00 aa|
|Average identity of full alignment:||92 %|
|Average coverage of the sequence by the domain:||4.26 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||8|
|Download:||download the raw HMM for this family|
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For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the Peptidase_C31 domain has been found. There are 1 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein seqence.
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