Crystal structure of a vertebrate smooth muscle myosin motor domain and its complex with the essential light chain: Visualization of the pre-power stroke state
Crystal structure of a vertebrate smooth muscle myosin motor domain and its complex with the essential light chain: Visualization of the pre-power stroke state
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DOI：
10.1016/s0092-8674(00)81598-6
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发表时间：
1998-09-04
期刊：
影响因子：
64.5
通讯作者：
Cohen, C
中科院分区：
文献类型：
--
作者：
Dominguez, R;Freyzon, Y;Cohen, C
一个表达的脊椎动物平滑肌肌球蛋白运动结构域（MD）以及一个运动结构域 - 必需轻链（ELC）复合物（MDE）的晶体结构已分别测定到2.9埃和3.5埃分辨率，它们的活性位点都有一个过渡态类似物（MgADP·AlF₄⁻）。具有ATP类似物（MgADP·BeFx）的MDE结构也测定到3.6埃分辨率。在所有这三种结构中，C末端区域的一个结构域——“转换器”，相对于无核苷酸的骨骼肌亚片段1（S1）旋转了约70度。我们发现MDE - BeFx和MDE - AlFx结构几乎相同，这与它们都与肌动蛋白弱结合的事实相符。对MDE - AlF₄⁻和无核苷酸的骨骼肌S1中杠杆臂位置的比较表明，在动力冲程期间可实现约10纳米的潜在位移。
The crystal structures of an expressed vertebrate smooth muscle myosin motor domain (MD) and a motor domain-essential light chain (ELC) complex (MDE), both with a transition state analog (MgADP . AlF4-) in the active site, have been determined to 2.9 Angstrom and 3.5 Angstrom resolution, respectively. The MDE structure with an ATP analog (MgADP . BeFx) was also determined to 3.6 Angstrom resolution. In all three structures, a domain of the C-terminal region, the "converter," is rotated similar to 70 degrees from that in nucleotide-free skeletal subfragment 1 (S1). We have found that the MDE-BeFx and MDE-AlFx structures are almost identical, consistent with the fact that they both bind weakly to actin. A comparison of the lever arm positions in MDE-AlF4- and in nucleotide-free skeletal S1 shows that a potential displacement of similar to 10 nm can be achieved during the power stroke.