This family includes eukaryotic, prokaryotic and archaeal proteins that bear similarity to a C-terminal region of human activator of 90 kDa heat shock protein ATPase homolog 1 (AHSA1/p38, Swiss:O95433). This protein is known to interact with the middle domain of Hsp90, and stimulate its ATPase activity [1]. It is probably a general upregulator of Hsp90 function, particularly contributing to its efficiency in conditions of increased stress [2]. p38 is also known to interact with the cytoplasmic domain of the VSV G protein, and may thus be involved in protein transport [3]. It has also been reported as being underexpressed in Down's syndrome. This region is found repeated in two members of this family (Swiss:Q8XY04 and Swiss:Q6MH87). The structure of YndB from Bacillus subtilis showed the helix-grip fold consisting of a beta-sheet with two small and one long alpha-helix which form a hydrophobic cavity that preferentially binds lipid-like molecules. This structure confirms its similarity with the eukaryote protein Aha1 and its classification as a member of the AHSA1 family) [4]. [1]. 12604615. Aha1 binds to the middle domain of Hsp90, contributes to client protein activation and stimulates the ATPase activity of the molecular chaperone. Lotz GP, Lin H, Harst A, Obermann WM;. J Biol Chem 2003;0:0-0. [2]. 12504007. Activation of the ATPase activity of hsp90 by the stress-regulated cochaperone aha1. Panaretou B, Siligardi G, Meyer P, Maloney A, Sullivan JK, Singh S, Millson SH, Clarke PA, Naaby-Hansen S, Stein R, Cramer R, Mollapour M, Workman P, Piper PW, Pearl LH, Prodromou C;. Mol Cell 2002;10:1307-1318. [3]. 11554768. p38: A. TRUNCATED at 1650 bytes (from Pfam)
- Date:
- 2024-10-16