This domain is found at the C-terminal end of human Proteasome activator complex subunit 4 (PSME4) and similar sequences from eukaryotes. PSME4 is an associated component of the proteasome that specifically recognises acetylated histones and promotes ...
This domain is found at the C-terminal end of human Proteasome activator complex subunit 4 (PSME4) and similar sequences from eukaryotes. PSME4 is an associated component of the proteasome that specifically recognises acetylated histones and promotes ATP- and ubiquitin -independent degradation of core histones during spermatogenesis and DNA damage response. This protein adopts a dome-like structure composed of HEAT repeat-like modules and a C-terminal domain that contains a hydrophobic -tyrosine-other motif (this entry). This domain, which adopts an all-alpha structure, is responsible for the interaction with the alpha-ring surface of the 20S [1].
The ordered regions of the yeast BLM10 or PA200 (human homologue), full-length protein encode 32 HEAT repeat (HR)-like modules [1], each comprising two helices joined by a turn, with adjacent repeats connected by a linker. Whereas a standard HEAT rep ...
The ordered regions of the yeast BLM10 or PA200 (human homologue), full-length protein encode 32 HEAT repeat (HR)-like modules [1], each comprising two helices joined by a turn, with adjacent repeats connected by a linker. Whereas a standard HEAT repeat is composed of ~50 residues, the BLM10 HEAT repeats are highly variable. The length of helices ranges from 8 to 35 residues, turns range from 2 to 87 residues, and linkers range from 1 to 88 residues, with the longest linker, between HR21 and HR22, containing additional secondary structures (two strands and three helices). BLM10_N is the N-terminal ordered region of the three in BLM10. BLM10 is found to surround the proteasome entry pore in the 1.2 MDa complex of proteasome and BLM10 to form a largely closed dome that is expected to restrict access of potential substrates. BLM10 and PA200 are predominantly nuclear and stimulate the degradation of model peptides, although they do not appear to stimulate the degradation of proteins, recognise ubiquitin, or utilise ATP [2].
