4L2C

X-ray structure of the C57R mutant of the iron superoxide dismutase from Pseudoalteromonas haloplanktis (crystal form I)

4L2C の概要

• エントリーDOI: 10.2210/pdb4l2c/pdb
• 関連するPDBエントリー: 3LIO 3LJ9 3LJF 4L2A 4L2B 4L2D
• 関連するBIRD辞書のPRD_ID: PRD_900006
• 分子名称: Superoxide dismutase [Fe], alpha-D-glucopyranose-(1-1)-alpha-D-glucopyranose, FE (III) ION, ... (4 entities in total)
• 機能のキーワード: superoxide dismutase, c57r mutant, oxidoreductase
• 由来する生物種: Pseudoalteromonas haloplanktis
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 86886.81

構造登録者

Russo Krauss, I.,Merlino, A.,Sica, F. (登録日: 2013-06-04, 公開日: 2014-02-26, 最終更新日: 2024-02-28)

主引用文献

Merlino, A.,Russo Krauss, I.,Castellano, I.,Ruocco, M.R.,Capasso, A.,De Vendittis, E.,Rossi, B.,Sica, F.
Structural and denaturation studies of two mutants of a cold adapted superoxide dismutase point to the importance of electrostatic interactions in protein stability.
Biochim.Biophys.Acta, 1844:632-640, 2014

PubMed Abstract: A peculiar feature of the psychrophilic iron superoxide dismutase from Pseudoalteromonas haloplanktis (PhSOD) is the presence in its amino acid sequence of a reactive cysteine (Cys57). To define the role of this residue, a structural characterization of the effect of two PhSOD mutations, C57S and C57R, was performed. Thermal and denaturant-induced unfolding of wild type and mutant PhSOD followed by circular dichroism and fluorescence studies revealed that C→R substitution alters the thermal stability and the resistance against denaturants of the enzyme, whereas C57S only alters the stability of the protein against urea. The crystallographic data on the C57R mutation suggest an involvement of the Arg side chain in the formation of salt bridges on protein surface. These findings support the hypothesis that the thermal resistance of PhSOD relies on optimization of charge-charge interactions on its surface. Our study contributes to a deeper understanding of the denaturation mechanism of superoxide dismutases, suggesting the presence of a structural dimeric intermediate between the native state and the unfolded state. This hypothesis is supported by the crystalline and solution data on the reduced form of the enzyme.

PubMed: 24440460
DOI: 10.1016/j.bbapap.2014.01.007

実験手法

X-RAY DIFFRACTION (1.66 Å)