A Stabilizing α/β-Hydrophobic Core Greatly Contributes to Hyperthermostability of Archaeal [P62A]Ssh10b

• DOI: 10.1021/bi8007593
• Publication Date: 2008-09-27T07:01:56Z
• Authors: Xianyang Fang; Qiu Cui; Yufeng Tong; Yingang Feng; Lu Shan; Li Huang; Jinfeng Wang
• Keywords: Thermostability; Hydrophobic effect; Denaturation (fissile materials); Folding (DSP implementation)

The hyperthermophilic Ssh10b from Sulfolobus shibatae is a member of the Sac10b family, which has been postulated to play role in chromosomal organization Archaea. capable significantly constraining negative DNA supercoils at elevated temperatures. In this study, solution structure dimeric P62A mutant ([P62A]Ssh10b) was determined by multidimensional NMR spectroscopy. backbone 15N dynamics, H/D exchange with and without denaturant GdmSCN, chemical thermal denaturation experiments were performed investigate molecular basis high thermostability [P62A]Ssh10b. Data analysis revealed an alpha/beta-hydrophobic core consisting two alpha-helices one beta-sheet are stabilized cooperative hydrophobic hydrogen-bonding interactions. This stabilizing [P62A]Ssh10b exhibiting highly restricted internal motions composed residues having protected amide protons solvent mostly means global unfolding process. K40N mutation greatly destabilizes because disturbs packing alpha-helix against reducing stability protein. comparison homologous mesophilic thermophilic proteins, it can be presumed that contributes