The 70 kDa heat-shock proteins (Hsp70s) are ATP-dependent molecular chaperones that contain an N-terminal nucleotide-binding domain (NBD) and a C-terminal substrate-binding domain. Hsp70s bind to misfolded/unfolded proteins and thereby prevent their aggregation. The ATP hydrolysis reaction in the NBD plays a key role in allosteric control of the binding of substrate proteins. In the present study, the neutron crystal structure of the NBD of Hsp72, a heat-inducible Hsp70 family member, was solved in complex with ADP in order to study the structure-function relationship with a focus on hydrogens. ADP bound to Hsp72 was fully deprotonated, and the catalytically important residues, including Asp10, Asp199 and Asp206, are also deprotonated. Neutron analysis also enabled the characterization of the water clusters in the NBD. Enzymatic assays and X-ray crystallographic analysis revealed that the Y149A mutation exhibited a higher ATPase activity and caused disruption of the water cluster and incorporation of an additional magnesium ion. Tyr149 was suggested to contribute to the low intrinsic ATPase activity and to stabilize the water cluster. Collectively, these structural studies will help to elucidate the molecular basis of the function of Hsp72.
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http://dx.doi.org/10.1107/S2052252522006297 | DOI Listing |
J Cheminform
January 2025
Oxford Protein Informatics Group, Department of Statistics, University of Oxford, Oxford, UK.
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View Article and Find Full Text PDFJ Microsc
January 2025
Department of Mechanical, Materials and Aerospace Engineering, University of Liverpool, Liverpool, UK.
Electron backscatter diffraction (EBSD) has developed over the last few decades into a valuable crystallographic characterisation method for a wide range of sample types. Despite these advances, issues such as the complexity of sample preparation, relatively slow acquisition, and damage in beam-sensitive samples, still limit the quantity and quality of interpretable data that can be obtained. To mitigate these issues, here we propose a method based on the subsampling of probe positions and subsequent reconstruction of an incomplete data set.
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January 2025
State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
Int J Mol Sci
December 2024
State Key Laboratory of Functions and Applications of Medicinal Plants & College of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, Guiyang 550014, China.
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