The determinants of the oligomeric structure in Hsp16.5 are encoded in the α‐crystallin domain

FEBS Letters

Koteiche, Hanane A¹  Mchaourab, Hassane S¹ 

[1] Department of Molecular Physiology and Biophysics, Vanderbilt University, 1161 21st Ave. South, 741 Light Hall, Nashville, TN 37232, USA

关键词: α-Crystallin domain;    Hsp16.5;    Hsp16.3;    Small heat-shock protein;    Electron paramagnetic resonance;    Site-directed spin labeling;    sHSP;    small heat-shock protein;    MJ Hsp16.5;    Methanococcus jannaschii heat-shock protein 16.5;    WT;    wild-type;    MTSSL;    methanethiosulfonate spin label;    cryo-EM;    cryogenic electron microscopy;    SDSL;    site-directed spin labeling;    CD;    circular dichroism;   

DOI  :  10.1016/S0014-5793(02)02688-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The determinants of the oligomeric assembly of Hsp16.5, a small heat-shock protein (sHSP) from Methanococcus jannaschii, were explored via site-directed truncation and site-directed spin labeling. For this purpose, subunit contacts around the two-, three- and four-fold symmetry axes were fingerprinted using patterns of proximities between nitroxide spin labels introduced at selected sites. The lack of change in this fingerprint in an N-terminal truncation of the protein demonstrates that the interactions are encoded in the α-crystallin domain. In contrast, the truncation of the N-terminal domain of Mycobacterium tuberculosis Hsp16.3, a bacterial sHSP with an equally short N-terminal region, results in the dissociation of the oligomer to a trimer. These results, in conjunction with those from previous truncation studies in mammalian sHSP, suggest that as the α-crystallin domain evolved to encode a smaller basic unit than the overall oligomer, the control of the assembly and dynamics of the oligomeric structure became encoded in the N-terminal domain.

【 授权许可】

Unknown