GEOMETRY OF INTERACTION OF METAL-IONS WITH SULFUR-CONTAINING LIGANDS IN PROTEIN STRUCTURES
GEOMETRY OF INTERACTION OF METAL-IONS WITH SULFUR-CONTAINING LIGANDS IN PROTEIN STRUCTURES
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DOI：
10.1021/bi00440a052
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发表时间：
1989-07-11
期刊：
影响因子：
2.9
通讯作者：
CHAKRABARTI, P
中科院分区：
文献类型：
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作者：
CHAKRABARTI, P
利用蛋白质数据库对蛋白质结构中半胱氨酸和甲硫氨酸残基与金属离子结合的几何构型进行了分析。金属离子与这些残基中的每一个具有不同的结合模式，并且这与金属中心的性质或蛋白质的类型无关。金属离子倾向于接近Met的硫约38 ° C。从垂直于通过原子C γ的平面开始，S. δ- C. ε..对于Cys，接近方向使得M. cntdot.. cntdot.S.gamma.- C β- C.alpha.扭转角约为±。90或180度。半胱氨酸残基的侧链构象受金属离子的存在的影响;存在从g+构象向g-和主要是t构象的转变。当在i - 3和i位的两个Cys残基与相同的金属中心结合时，对于这样的残基χ 1和M ω，残基i对金属结合的几何形状似乎有一些限制。cntdot.. cntdot.S.gamma.- C β- C.alpha.角度可能在60 °左右。和270 °，分别与金属离子配位的Met和Cys残基通常来自蛋白质结构的卷曲或转角区域。
An analysis of the geometry of binding of metal ions by cysteine a methionine residues in protein structures has been made by using the Protein Data Bank. Metal ions have a distinct mode of binding to each of these residues, and this is independent of the nature of the metal center or the type of protein. Metal ions tend to approach the sulfur of Met roughly 38.degree. from the perpendicular to the plane through atoms C.gamma.-S.delta.-C.epsilon.. For the Cys, the approach direction is such that the M.cntdot..cntdot..cntdot.S.gamma.-C.beta.-C.alpha. torsional angle is about .+-. 90 or 180.degree.. The side-chain conformation of the cysteine residue is affected by the presence of the metal ion; there is a shift from the g+ conformation toward g- and mainly t conformations. When two Cys residues at positions i - 3 and i bind to the same metal center, there appears to be some restriction on the geometry of metal binding by the residue i; for such a residue .chi.1 and M.cntdot..cntdot..cntdot.S.gamma.-C.beta.-C.alpha. angles are likely to be around 60.degree. and 270.degree., respectively. Met and Cys residues coordinating to a metal ion are usually from coil or turn regions of the protein structure.