Refinement of the 7 Fe ferredoxin from Azotobacter vinelandii at 1.9 A resolution.
Refinement of the 7 Fe ferredoxin from Azotobacter vinelandii at 1.9 A resolution.
复制标题
以 1.9 A 分辨率精制来自 Azotobacter vinelandii 的 7 Fe 铁氧还蛋白。
DOI：
10.1016/0022-2836(89)90225-8
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发表时间：
1989
影响因子：
5.6
通讯作者：
Stout,CD
中科院分区：
文献类型：
--
作者：
Stout,CD
最近重新确定的来自 Azotobacter vinelandii 的 7 Fe 铁氧还蛋白的结构已根据新的 1.9 Å 数据集进行了精炼。对于所有 9586 个观察到的 8.0 至 1.9 Å 反射，晶体学 R 因子均为 0.215。该模型包含106个氨基酸残基、两个FeS簇和21个水分子。与理想键和角度的均方根偏差分别为 0.014 Å 和 3.3 °。精修证实了两个游离半胱氨酸的存在：C11 的硫醇与 K100 的侧链结合； C24的硫醇距[4 Fe4 S]簇的无机硫3.35 Å。细化证实了 3 Fe 团簇的 [3 Fe4 S] 模型。两个FeS簇具有相似的键距和角度。如果省略 7 Fe 铁氧还蛋白的残基 9、10、29 和 30，则残基 1 至 57 的蛋白质结构在主链 N、CA 和 C 原子的 8 Fe 铁氧还蛋白结构的残基 1 至 53 上重叠在 0.85 Å 范围内。这些残基是与 7 Fe 铁氧还蛋白延伸的 C 端链残基接触的两个环的一部分。
The recently redetermined structure of the 7 Fe ferredoxin fromAzotobacter vinelandiihas been refined against a new 1.9 Å data set. The crystallographicR-factor is 0.215 for all 9586 observed reflections 8.0 to 1.9 Å. The model contains 106 amino acid residues, two FeS clusters and 21 water molecules. The root-mean-square deviations from ideality of bonds and angles are 0.014 Å and 3.3 °, respectively. The refinement confirms the presence of two free cysteines: the thiol of C11 is in association with the side-chain of K100; the thiol of C24 is 3.35 Å from inorganic sulfur of the [4 Fe4 S] cluster. The refinement confirms a [3 Fe4 S] model for the 3 Fe cluster. The two FeS clusters have similar bond distances and angles. The structure of the protein for residues 1 to 57 superposes within 0.85 Å on residues 1 to 53 of the 8 Fe ferredoxin structure for main-chain N, CA and C atoms, if residues 9, 10, 29 and 30 of 7 Fe ferredoxin are omitted. These residues are part of two loops in contact with residues of the extended C-terminal chain of 7 Fe ferredoxin.