| Type: | Family | Name: | Proteasome B-type subunit |
| Description: | 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 homologues to eubacterial HslU (ClpY, clpX) have also been demonstrated in to be present in the genome of trypanosomatid protozoa [].The proteasome (or macropain) () [, , , , ] is a eukaryotic andarchaeal multicatalytic proteinase complex that seems to be involved in an ATP/ubiquitin-dependent nonlysosomal proteolytic pathway. In eukaryotes theproteasome 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, a peptidase, and HslU (), the ATPase and chaperone belonging to the AAA/Clp/Hsp100 family. The crystal structure of Thermotoga maritimaHslV has been determined to 2.1-A resolution. The structure of the dodecameric enzyme is well conserved compared to those from Escherichia coliand Haemophilus influenzae[, ].This family consists of the beta (or B type) subunits of the eukaryotic proteasome as well as the archaeal and bacterial proteasomes. These proteins belong to family T1 in the classification of peptidases. | Short Name: | Proteasome_suB-type |
