3AK2

Superoxide dismutase from Aeropyrum pernix K1, Mn-bound form

3AK2 の概要

• エントリーDOI: 10.2210/pdb3ak2/pdb
• 関連するPDBエントリー: 3AK1 3AK3
• 分子名称: Superoxide dismutase [Mn/Fe], MANGANESE (II) ION, 1,2-ETHANEDIOL, ... (4 entities in total)
• 機能のキーワード: superoxide dismutase, cambialistic, oxidoreductase
• 由来する生物種: Aeropyrum pernix
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 99774.08

構造登録者

Nakamura, T.,Uegaki, K. (登録日: 2010-06-30, 公開日: 2011-02-02, 最終更新日: 2023-11-01)

主引用文献

Nakamura, T.,Torikai, K.,Uegaki, K.,Morita, J.,Machida, K.,Suzuki, A.,Kawata, Y.
Crystal structure of the cambialistic superoxide dismutase from Aeropyrum pernix K1 - insights into the enzyme mechanism and stability
Febs J., 278:598-609, 2011

PubMed Abstract: Aeropyrum pernix K1, an aerobic hyperthermophilic archaeon, produces a cambialistic superoxide dismutase that is active in the presence of either of Mn or Fe. The crystal structures of the superoxide dismutase from A. pernix in the apo, Mn-bound and Fe-bound forms were determined at resolutions of 1.56, 1.35 and 1.48 Å, respectively. The overall structure consisted of a compact homotetramer. Analytical ultracentrifugation was used to confirm the tetrameric association in solution. In the Mn-bound form, the metal was in trigonal bipyramidal coordination with five ligands: four side chain atoms and a water oxygen. One aspartate and two histidine side chains ligated to the central metal on the equatorial plane. In the Fe-bound form, an additional water molecule was observed between the two histidines on the equatorial plane and the metal was in octahedral coordination with six ligands. The additional water occupied the postulated superoxide binding site. The thermal stability of the enzyme was compared with superoxide dismutase from Thermus thermophilus, a thermophilic bacterium, which contained fewer ion pairs. In aqueous solution, the stabilities of the two enzymes were almost identical but, when the solution contained ethylene glycol or ethanol, the A. pernix enzyme had significantly higher thermal stability than the enzyme from T. thermophilus. This suggests that dominant ion pairs make A. pernix superoxide dismutase tolerant to organic media.

PubMed: 21182595
DOI: 10.1111/j.1742-4658.2010.07977.x

実験手法

X-RAY DIFFRACTION (1.35 Å)