3E2C

Escherichia coli Bacterioferritin Mutant E128R/E135R

3E2C の概要

• エントリーDOI: 10.2210/pdb3e2c/pdb
• 分子名称: Bacterioferritin, ZINC ION, SULFATE ION, ... (6 entities in total)
• 機能のキーワード: diiron site, iron storage, metal-binding, heme, iron, oxidoreductase
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 38952.54

構造登録者

Wong, S.G.,Tom-Yew, S.A.L.,Lewin, A.,Le Brun, N.E.,Moore, G.R.,Murphy, M.E.P.,Mauk, A.G. (登録日: 2008-08-05, 公開日: 2009-05-12, 最終更新日: 2024-02-21)

主引用文献

Wong, S.G.,Tom-Yew, S.A.,Lewin, A.,Le Brun, N.E.,Moore, G.R.,Murphy, M.E.,Mauk, A.G.
Structural and Mechanistic Studies of a Stabilized Subunit Dimer Variant of Escherichia coli Bacterioferritin Identify Residues Required for Core Formation.
J.Biol.Chem., 284:18873-18881, 2009

PubMed Abstract: Bacterioferritin (BFR) is a bacterial member of the ferritin family that functions in iron metabolism and protects against oxidative stress. BFR differs from the mammalian protein in that it is comprised of 24 identical subunits and is able to bind 12 equivalents of heme at sites located between adjacent pairs of subunits. The mechanism by which iron enters the protein to form the dinuclear (ferroxidase) catalytic site present in every subunit and the mineralized iron core housed within the 24-mer is not well understood. To address this issue, the properties of a catalytically functional assembly variant (E128R/E135R) of Escherichia coli BFR are characterized by a combination of crystallography, site-directed mutagenesis, and kinetics. The three-dimensional structure of the protein (1.8 A resolution) includes two ethylene glycol molecules located on either side of the dinuclear iron site. One of these ethylene glycol molecules is integrated into the surface of the protein that would normally be exposed to solvent, and the other is integrated into the surface of the protein that would normally face the iron core where it is surrounded by the anionic residues Glu(47), Asp(50), and Asp(126). We propose that the sites occupied by these ethylene glycol molecules define regions where iron interacts with the protein, and, in keeping with this proposal, ferroxidase activity decreases significantly when they are replaced with the corresponding amides.

PubMed: 19439409
DOI: 10.1074/jbc.M901747200

実験手法

X-RAY DIFFRACTION (1.8 Å)