ジャーナル: Nat Struct Mol Biol / 年: 2010 タイトル: Solid-state NMR and SAXS studies provide a structural basis for the activation of alphaB-crystallin oligomers. 著者: Stefan Jehle / Ponni Rajagopal / Benjamin Bardiaux / Stefan Markovic / Ronald Kühne / Joseph R Stout / Victoria A Higman / Rachel E Klevit / Barth-Jan van Rossum / Hartmut Oschkinat / 要旨: The small heat shock protein alphaB-crystallin (alphaB) contributes to cellular protection against stress. For decades, high-resolution structural studies on oligomeric alphaB have been confounded by ...The small heat shock protein alphaB-crystallin (alphaB) contributes to cellular protection against stress. For decades, high-resolution structural studies on oligomeric alphaB have been confounded by its polydisperse nature. Here, we present a structural basis of oligomer assembly and activation of the chaperone using solid-state NMR and small-angle X-ray scattering (SAXS). The basic building block is a curved dimer, with an angle of approximately 121 degrees between the planes of the beta-sandwich formed by alpha-crystallin domains. The highly conserved IXI motif covers a substrate binding site at pH 7.5. We observe a pH-dependent modulation of the interaction of the IXI motif with beta4 and beta8, consistent with a pH-dependent regulation of the chaperone function. N-terminal region residues Ser59-Trp60-Phe61 are involved in intermolecular interaction with beta3. Intermolecular restraints from NMR and volumetric restraints from SAXS were combined to calculate a model of a 24-subunit alphaB oligomer with tetrahedral symmetry.
分子量: 20191.930 Da / 分子数: 2 断片: Alpha-crystallin domain homodimer in oligomers of alphaB-crystallin 由来タイプ: 組換発現 / 由来: (組換発現) Homo sapiens (ヒト) / 遺伝子: CRYAB, CRYA2 / 発現宿主: Escherichia coli (大腸菌) / 参照: UniProt: P02511
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THE HOMOGENEOUS PART OF THE ALPHA-CRYSTALLIN DOMAIN DIMER IN OLIGOMERS OF HUMAN ALPHAB CRYSTALLIN ...THE HOMOGENEOUS PART OF THE ALPHA-CRYSTALLIN DOMAIN DIMER IN OLIGOMERS OF HUMAN ALPHAB CRYSTALLIN IS SHOWN IN THIS STRUCTURE. RESIDUES THAT SHOW A SINGLE NMR SIGNAL SET FOR C', CA AND CB WERE INCLUDED IN THE STRUCTURE CALCULATION. SUBJECT OF THE STUDY WAS THE FULL LENGTH PROTEIN (UNIPROT ID P02511).