Solid-state NMR and SAXS studies provide a structural basis for the activation of alphaB-crystallin oligomers.

ABSTRACT: 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 resi

SUBMITTER: Jehle S 

PROVIDER: S-EPMC2957905 | biostudies-literature | 2010 Sep

REPOSITORIES: biostudies-literature