3LFO

Crystal structure of T. celer L30e E90A/R92A variant

3LFO の概要

• エントリーDOI: 10.2210/pdb3lfo/pdb
• 関連するPDBエントリー: 1H7M
• 分子名称: 50S ribosomal protein L30e (2 entities in total)
• 機能のキーワード: ribosomal protein, l30e, thermophilic, globular protein
• 由来する生物種: Thermococcus celer
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 10837.56

構造登録者

Chan, C.H.,Wong, K.B. (登録日: 2010-01-18, 公開日: 2010-04-14, 最終更新日: 2023-11-01)

主引用文献

Chan, C.H.,Yu, T.H.,Wong, K.B.
Stabilizing salt-bridge enhances protein thermostability by reducing the heat capacity change of unfolding.
Plos One, 6:e21624-e21624, 2011

PubMed Abstract: Most thermophilic proteins tend to have more salt bridges, and achieve higher thermostability by up-shifting and broadening their protein stability curves. While the stabilizing effect of salt-bridge has been extensively studied, experimental data on how salt-bridge influences protein stability curves are scarce. Here, we used double mutant cycles to determine the temperature-dependency of the pair-wise interaction energy and the contribution of salt-bridges to ΔC(p) in a thermophilic ribosomal protein L30e. Our results showed that the pair-wise interaction energies for the salt-bridges E6/R92 and E62/K46 were stabilizing and insensitive to temperature changes from 298 to 348 K. On the other hand, the pair-wise interaction energies between the control long-range ion-pair of E90/R92 were negligible. The ΔC(p) of all single and double mutants were determined by Gibbs-Helmholtz and Kirchhoff analyses. We showed that the two stabilizing salt-bridges contributed to a reduction of ΔC(p) by 0.8-1.0 kJ mol⁻¹ K⁻¹. Taken together, our results suggest that the extra salt-bridges found in thermophilic proteins enhance the thermostability of proteins by reducing ΔC(p), leading to the up-shifting and broadening of the protein stability curves.

PubMed: 21720566
DOI: 10.1371/journal.pone.0021624

実験手法

X-RAY DIFFRACTION (1.8 Å)