SOLUTION STRUCTURE OF CALCIUM-FREE CALMODULIN
SOLUTION STRUCTURE OF CALCIUM-FREE CALMODULIN
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DOI：
10.1038/nsb0995-768
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发表时间：
1995-09-01
期刊：
影响因子：
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通讯作者：
BAX, A
中科院分区：
文献类型：
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作者：
KUBONIWA, H;TJANDRA, N;BAX, A
在没有 Ca2+ 的情况下，钙调蛋白的三维结构已通过三维和四维异核 NMR 实验确定，包括 ROE、同位素过滤结合反向标记以及 700 多个三键 I 偶联的测量。与该蛋白质的 Ca2+ 连接状态类似，它由两个由柔性接头分隔的小球状结构域组成，两个结构域之间没有稳定的直接接触。在没有 Ca2+ 的情况下，两个球状结构域中的每一个中的四个螺旋形成一个高度扭曲的束，并由短的反平行 β 折叠覆盖。这种排列在性质上与肌钙蛋白 C 的无 Ca2+ N 端结构域的晶体结构中观察到的相似。
The three-dimensional structure of calmodulin in the absence of Ca2+ has been determined by three- and four-dimensional heteronuclear NMR experiments, including ROE, isotope-filtering combined with reverse labelling, and measurement of more than 700 three-bond I-couplings. In analogy with the Ca2+-ligated state of this protein, it consists of two small globular domains separated by a flexible linker, with no stable, direct contacts between the two domains. In the absence of Ca2+, the four helices in each of the two globular domains form a highly twisted bundle, capped by a short anti-parallel beta-sheet. This arrangement is qualitatively similar to that observed in the crystal structure of the Ca2+-free N-terminal domain of troponin C.