1usv

From Proteopedia

The Structure of the complex between Aha1 and HSP90

Structural highlights

1usv is a 8 chain structure with sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.7Å
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

AHA1_YEAST Co-chaperone that binds to the molecular chaperone HSP82 and stimulates its ATPase activity. Binding to HSP82 promotes a conformational switch in the catalytic loop of HSP82, facilitating the interaction of the catalytic 'Arg-380' with ATP in the N-terminal nucleotide-binding domain. Although not essential, it confers thermotolerance when intracellular levels of HSP82 are limiting.^[1] ^[2]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Hsp90 is a molecular chaperone essential for the activation and assembly of many key eukaryotic signalling and regulatory proteins. Hsp90 is assisted and regulated by co-chaperones that participate in an ordered series of dynamic multiprotein complexes, linked to Hsp90 conformationally coupled ATPase cycle. The co-chaperones Aha1 and Hch1 bind to Hsp90 and stimulate its ATPase activity. Biochemical analysis shows that this activity is dependent on the N-terminal domain of Aha1, which interacts with the central segment of Hsp90. The structural basis for this interaction is revealed by the crystal structure of the N-terminal domain (1-153) of Aha1 (equivalent to the whole of Hch1) in complex with the middle segment of Hsp90 (273-530). Structural analysis and mutagenesis show that binding of N-Aha1 promotes a conformational switch in the middle-segment catalytic loop (370-390) of Hsp90 that releases the catalytic Arg 380 and enables its interaction with ATP in the N-terminal nucleotide-binding domain of the chaperone.

Structural basis for recruitment of the ATPase activator Aha1 to the Hsp90 chaperone machinery.,Meyer P, Prodromou C, Liao C, Hu B, Roe SM, Vaughan CK, Vlasic I, Panaretou B, Piper PW, Pearl LH EMBO J. 2004 Mar 24;23(6):1402-10. PMID:15039704^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ 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. Activation of the ATPase activity of hsp90 by the stress-regulated cochaperone aha1. Mol Cell. 2002 Dec;10(6):1307-18. PMID:12504007
↑ Lotz GP, Lin H, Harst A, Obermann WM. Aha1 binds to the middle domain of Hsp90, contributes to client protein activation, and stimulates the ATPase activity of the molecular chaperone. J Biol Chem. 2003 May 9;278(19):17228-35. Epub 2003 Feb 24. PMID:12604615 doi:http://dx.doi.org/10.1074/jbc.M212761200
↑ Meyer P, Prodromou C, Liao C, Hu B, Roe SM, Vaughan CK, Vlasic I, Panaretou B, Piper PW, Pearl LH. Structural basis for recruitment of the ATPase activator Aha1 to the Hsp90 chaperone machinery. EMBO J. 2004 Mar 24;23(6):1402-10. PMID:15039704 doi:http://dx.doi.org/10.1038/sj.emboj.7600141