TY - JOUR AU - Oroz, Javier AU - Blair, Laura J AU - Zweckstetter, Markus TI - Dynamic Aha1 co-chaperone binding to human Hsp90. JO - Protein science VL - 28 IS - 9 SN - 0961-8368 CY - Bethesda, Md. PB - Protein Society M1 - DZNE-2020-07198 SP - 1545-1551 PY - 2019 AB - Hsp90 is an essential chaperone that requires large allosteric changes to determine its ATPase activity and client binding. The co-chaperone Aha1, which is the major ATPase stimulator in eukaryotes, is important for regulation of Hsp90's allosteric timing. Little is known, however, about the structure of the Hsp90/Aha1 complex. Here, we characterize the solution structure of unmodified human Hsp90/Aha1 complex using NMR spectroscopy. We show that the 214-kDa complex forms by a two-step binding mechanism and adopts multiple conformations in the absence of nucleotide. Aha1 induces structural changes near Hsp90's nucleotide-binding site, providing a basis for its ATPase-enhancing activity. Our data reveal important aspects of this pivotal chaperone/co-chaperone interaction and emphasize the relevance of characterizing dynamic chaperone structures in solution. KW - Allosteric Regulation KW - Binding Sites KW - HSP90 Heat-Shock Proteins: chemistry KW - HSP90 Heat-Shock Proteins: metabolism KW - Humans KW - Models, Molecular KW - Molecular Chaperones: chemistry KW - Molecular Chaperones: metabolism KW - Molecular Weight KW - Nuclear Magnetic Resonance, Biomolecular KW - Protein Binding KW - Protein Conformation LB - PUB:(DE-HGF)16 C6 - pmid:31299134 C2 - pmc:PMC6699087 DO - DOI:10.1002/pro.3678 UR - https://pub.dzne.de/record/140876 ER -