3OT7

Escherichia coli apo-manganese superoxide dismutase

3OT7 の概要

• エントリーDOI: 10.2210/pdb3ot7/pdb
• 分子名称: Superoxide dismutase [Mn] (2 entities in total)
• 機能のキーワード: oxidoreductase, superoxide dismutase, manganese enzyme, metalloprotein, dna binding
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 91987.51

構造登録者

Whittaker, M.M.,Lerch, T.F.,Kirillova, O.,Chapman, M.S.,Whittaker, J.W. (登録日: 2010-09-10, 公開日: 2010-12-22, 最終更新日: 2023-09-06)

主引用文献

Whittaker, M.M.,Lerch, T.F.,Kirillova, O.,Chapman, M.S.,Whittaker, J.W.
Subunit dissociation and metal binding by Escherichia coli apo-manganese superoxide dismutase.
Arch.Biochem.Biophys., 505:213-225, 2011

PubMed Abstract: Metal binding by apo-manganese superoxide dismutase (apo-MnSOD) is essential for functional maturation of the enzyme. Previous studies have demonstrated that metal binding by apo-MnSOD is conformationally gated, requiring protein reorganization for the metal to bind. We have now solved the X-ray crystal structure of apo-MnSOD at 1.9Å resolution. The organization of active site residues is independent of the presence of the metal cofactor, demonstrating that protein itself templates the unusual metal coordination geometry. Electrophoretic analysis of mixtures of apo- and (Mn₂)-MnSOD, dye-conjugated protein, or C-terminal Strep-tag II fusion protein reveals a dynamic subunit exchange process associated with cooperative metal binding by the two subunits of the dimeric protein. In contrast, (S126C) (SS) apo-MnSOD, which contains an inter-subunit covalent disulfide-crosslink, exhibits anti-cooperative metal binding. The protein concentration dependence of metal uptake kinetics implies that protein dissociation is involved in metal binding by the wild type apo-protein, although other processes may also contribute to gating metal uptake. Protein concentration dependent small-zone size exclusion chromatography is consistent with apo-MnSOD dimer dissociation at low protein concentration (K(D)=1×10⁻⁵ M). Studies on metal uptake by apo-MnSOD in Escherichia coli cells show that the protein exhibits similar behavior in vivo and in vitro.

PubMed: 21044611
DOI: 10.1016/j.abb.2010.10.021

実験手法

X-RAY DIFFRACTION (1.901 Å)