1H NMR studies of plastocyanin from Scenedesmus obliquus: complete sequence-specific assignment, secondary structure analysis, and global fold.
1H NMR studies of plastocyanin from Scenedesmus obliquus: complete sequence-specific assignment, secondary structure analysis, and global fold.
复制标题
斜生栅藻质体蓝素的 1H NMR 研究：完整的序列特异性分配、二级结构分析和整体折叠。
DOI：
10.1021/bi00420a033
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发表时间：
1988
期刊：
影响因子：
2.9
通讯作者：
Wright,PE
中科院分区：
文献类型：
--
作者：
Moore,JM;Chazin,WJ;Powls,R;Wright,PE
利用二维{sup 1}H NMR方法对绿色栅藻质体蓝蛋白的97个氨基酸残基进行了序列特异性共振归属。获得了所有骨架质子和大多数侧链质子的归属。自旋系统的识别在很大程度上依赖于观察到的骨干酰胺质子的中继连接。通过使用顺序分配程序进行序列特异性分配。在此过程中，鉴定了在原始氨基酸序列中未检测到的额外缬氨酸残基。从骨架质子之间的特征NOE连接性，耦合常数值和缓慢交换酰胺质子的观察中确定了规则二级结构的元素。溶液中的蛋白质含有八条β链、一段短螺旋、五个反向转角和五个环。基于广泛的交叉链NOE连接性，{β}-链可以排列成两个{β}片层。从NMR实验中确定的链折叠拓扑结构是希腊键{β}-桶，并且与在溶液中观察到的菜豆质体蓝素和在结晶状态下观察到的白杨质体蓝素相似。虽然总体结构相似，但S.已鉴定出拟南芥和高等植物质体蓝素。
Two-dimensional {sup 1}H NMR methods have been used to make sequence-specific resonance assignments for the 97 amino acid residues of the plastocyanin from the green alga Scenedesmus obliquus. Assignments were obtained for all backbone protons and the majority of the side-chain protons. Spin system identification relied heavily on the observation of relayed connectivities to the backbone amide proton. Sequence-specific assignments were made by using the sequential assignment procedure. During this process, an extra valine residue was identified that had not been detected in the original amino acid sequence. Elements of regular secondary structure were identified from characteristic NOE connectivities between backbone protons, coupling constant values, and the observation of slowly exchanging amide protons. The protein in solution contains eight {beta}-strands, one short segment of helix, five reverse turns, and five loops. The {beta}-strands may be arranged into two {beta}sheets on the basis of extensive cross-strand NOE connectivities. The chain-folding topology determined from the NMR experiments is that of a Greek key {beta}-barrel and is similar to that observed for French bean plastocyanin in solution and poplar plastocyanin in the crystalline state. While the overall structures are similar, several differences in local structure between the S. obliquus and higher plant plastocyanins have been identified.