Summary: Proteasome subunit
Proteasome subunit Provide feedback
The proteasome is a multisubunit structure that degrades proteins. Protein degradation is an essential component of regulation because proteins can become misfolded, damaged, or unnecessary. Proteasomes and their homologues vary greatly in complexity: from HslV (heat shock locus v), which is encoded by 1 gene in bacteria, to the eukaryotic 20S proteasome, which is encoded by more than 14 genes . Recently evidence of two novel groups of bacterial proteasomes was proposed. The first is Anbu, which is sparsely distributed among cyanobacteria and proteobacteria . The second is call beta-proteobacteria proteasome homologue (BPH) .
External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR001353
ATP-dependent protease complexes are present in all three kingdoms of life, where they rid the cell of misfolded or damaged proteins and control the level of certain regulatory proteins. They include the proteasome in Eukaryotes, Archaea, and Actinomycetales and the HslVU (ClpQY, clpXP) complex in other eubacteria. Genes homologous to eubacterial HslV (ClpQ) and HslU (ClpY, clpX) have also been demonstrated in to be present in the genome of trypanosomatid protozoa [PUBMED:12446803].
The proteasome (or macropain) (EC) [PUBMED:7682410, PUBMED:2643381, PUBMED:1317508, PUBMED:7697118, PUBMED:8882582] is a eukaryotic and archaeal multicatalytic proteinase complex that seems to be involved in an ATP/ubiquitin-dependent nonlysosomal proteolytic pathway. In eukaryotes the proteasome is composed of about 28 distinct subunits which form a highly ordered ring-shaped structure (20S ring) of about 700 kDa. Most proteasome subunits can be classified on the basis of sequence similarities into two groups, alpha (A) and beta (B).
The prokaryotic ATP-dependent proteasome is coded for by the heat-shock locus VU (HslVU). It consists of HslV, the protease (MEROPS peptidase subfamily T1B), and HslU, INTERPRO, the ATPase and chaperone belonging to the AAA/Clp/Hsp100 family. The crystal structure of Thermotoga maritima HslV has been determined to 2.1-A resolution. The structure of the dodecameric enzyme is well conserved compared to those from Escherichia coli and Haemophilus influenzae [PUBMED:12646382, PUBMED:12823960].
This entry contains threonine peptidases and non-peptidase homologs belong to MEROPS peptidase family T1 (proteasome family, clan PB(T)). The family consists of the protease components of the archaeal and bacterial proteasomes and the alpha and beta subunits of the eukaryotic proteasome.
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
|Cellular component||proteasome core complex (GO:0005839)|
|Molecular function||threonine-type endopeptidase activity (GO:0004298)|
|Biological process||proteolysis involved in cellular protein catabolic process (GO:0051603)|
- the number of sequences which exhibit this architecture
a textual description of the architecture, e.g. Gla, EGF x 2, Trypsin.
This example describes an architecture with one
Gladomain, followed by two consecutive
EGFdomains, and finally a single
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In the N-terminal nucleophile aminohydrolases (Ntn hydrolases) the N-terminal residue provides two catalytic groups, nucleophile and proton donor. These enzymes use the side chain of the amino-terminal residue, incorporated in a beta-sheet, as the nucleophile in the catalytic attack at the carbonyl carbon. The nucleophile is cysteine in GAT, serine in penicillin acylase, and threonine in the proteasome. All the enzymes share an unusual fold in which the nucleophile and other catalytic groups occupy equivalent sites. This fold provides both the capacity for nucleophilic attack and the possibility of autocatalytic processing .
The clan contains the following 14 members:AAT Asparaginase_2 CBAH DUF1933 DUF3700 G_glu_transpept GATase_2 GATase_4 GATase_6 GATase_7 Penicil_amidase Peptidase_C69 Phospholip_B Proteasome
We make a range of alignments for each Pfam-A family:
- the curated alignment from which the HMM for the family is built
- the alignment generated by searching the sequence database using the HMM
- Representative Proteomes (RPs) at 15%, 35%, 55% and 75% co-membership thresholds
- alignment generated by searching the NCBI sequence database using the family HMM
- alignment generated by searching the metagenomics sequence database using the family HMM
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Curation and family details
|Author:||Finn RD, Bateman A, Valas RE|
|Number in seed:||174|
|Number in full:||10806|
|Average length of the domain:||173.50 aa|
|Average identity of full alignment:||21 %|
|Average coverage of the sequence by the domain:||77.89 %|
|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:||21|
|Download:||download the raw HMM for this family|
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There are 3 interactions for this family. More...
We determine these interactions using iPfam, which considers the interactions between residues in three-dimensional protein structures and maps those interactions back to Pfam families. You can find more information about the iPfam algorithm in the journal article that accompanies the website.
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 Proteasome domain has been found. There are 1970 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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