2I5M

Crystal structure of Bacillus subtilis cold shock protein CspB variant A46K S48R

2I5M の概要

• エントリーDOI: 10.2210/pdb2i5m/pdb
• 関連するPDBエントリー: 1CSP 1CSQ 2ES2 2I5L
• 分子名称: Cold shock protein cspB, MAGNESIUM ION (3 entities in total)
• 機能のキーワード: oligonucleotide/oligosaccharide binding fold, cold shock domain, beta-barrel, dna binding protein, expression regulator, gene regulation
• 由来する生物種: Bacillus subtilis
• 細胞内の位置: Cytoplasm, nucleoid : P32081
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 7524.65

構造登録者

Max, K.E.A.,Heinemann, U. (登録日: 2006-08-25, 公開日: 2007-05-22, 最終更新日: 2023-08-30)

主引用文献

Max, K.E.,Wunderlich, M.,Roske, Y.,Schmid, F.X.,Heinemann, U.
Optimized variants of the cold shock protein from in vitro selection: structural basis of their high thermostability.
J.Mol.Biol., 369:1087-1097, 2007

PubMed Abstract: The bacterial cold shock proteins (Csp) are widely used as models for the experimental and computational analysis of protein stability. In a previous study, in vitro evolution was employed to identify strongly stabilizing mutations in Bs-CspB from Bacillus subtilis. The best variant found by this approach contained the mutations M1R, E3K and K65I, which raised the midpoint of thermal unfolding of Bs-CspB from 53.8 degrees C to 83.7 degrees C, and increased the Gibbs free energy of stabilization by 20.9 kJ mol(-1). Another selected variant with the two mutations A46K and S48R was stabilized by 11.1 kJ mol(-1). To elucidate the molecular basis of these stabilizations, we determined the crystal structures of these two Bs-CspB variants. The mutated residues are generally well ordered and provide additional stabilizing interactions, such as charge interactions, additional hydrogen bonds and improved side-chain packing. Several mutations improve the electrostatic interactions, either by the removal of unfavorable charges (E3K) or by compensating their destabilizing interactions (A46K, S48R). The stabilizing mutations are clustered at a contiguous surface area of Bs-CspB, which apparently is critically important for the stability of the beta-barrel structure but not well optimized in the wild-type protein.

PubMed: 17481655
DOI: 10.1016/j.jmb.2007.04.016

実験手法

X-RAY DIFFRACTION (2.3 Å)