ALPHA-HELICAL COILED COILS - MORE FACTS AND BETTER PREDICTIONS
ALPHA-HELICAL COILED COILS - MORE FACTS AND BETTER PREDICTIONS
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DOI：
10.1126/science.8290957
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发表时间：
1994-01-28
期刊：
影响因子：
56.9
通讯作者：
PARRY, DAD
中科院分区：
文献类型：
--
作者：
COHEN, C;PARRY, DAD
a-螺旋螺旋结构终于流行起来了。以前，只有纤维蛋白爱好者——被认为是古老制度的残余——对大的、被认为是沉闷的蛋白质感兴趣，如角蛋白、肌球蛋白和纤维蛋白原，它们具有卷曲的棒状结构。有两件事改变了这种局面——第一件事进展缓慢，第二件事几乎立即发生。到20世纪80年代中期，a-螺旋线圈在蛋白质结构中的应用比人们想象的要广泛得多。蛋白质序列中7个氨基酸（七肽）重复序列的存在[通常被称为位置a到g，其中a和d通常是极性的](I)及其卷曲的卷曲状结构的含义提供了一种仅通过一级结构识别三级结构的方法-只需通过检查（尽管用知情的眼睛）。在氨基酸序列中检测盘绕线圈的统计方法加强了这种方法(2)。由于cDNA技术，许多新的序列成为可能，并且卷曲线圈的特殊特征可以在不同的蛋白质中识别(3)。第二件事发生在2年前：这是酵母转录因子GCN4的33个残基亮氨酸拉链部分的x射线结构（以1.8 A分辨率）的测定(4)。事实上，亮氨酸拉链的发现导致了盘绕线圈的重新发现！从低分辨率x射线晶体结构(5)、序列分析和原肌凝蛋白和肌凝蛋白等蛋白质的模型构建(6)中，我们现在可以非常详细地看到许多关于盘绕线圈结构的推论的物理基础。随后，其他高分辨率的螺旋状蛋白结构（包括天然的和设计的）也变得可用，这些也使我们能够改进当前的预测方法。从序列中预测盘绕线圈的第一步是通过目测来定位序列中的盘绕线圈区域
The a-helical coiled-coil structure is finally in fashion. Previously, only fibrous protein enthusiasts--eonsidered to be the remnants of an ancien regime-interested themselves in large, supposedly dull proteins such as keratin, myosin, and fibrinogen that have coiled-coil rod domain structures. Two events changed this situation-the first slowly, the second almost immediately. By the mid-80s, it had become apparent that a-helical coiled coils were far more widespread in protein structures than had been imagined. The presence of a seven-amino acid (heptad) repeat in the sequence of a protein [conventionally referred to as positions a to g, where a and d are generally apolar](I) and its implication of a coiled coil-like structure provided a means to recognize tertiary structure from primary structure alone-simply by inspection (albeit with an informed eye). Statistical measures to detect coiled coils in amino acid sequences have strengthened this approach (2). Thanks to cDNA technology, many new sequences became available, and the special features of the coiled coil could be recognized in diverse proteins (3). The second event occurred but 2 years ago: This was the determination of the x-ray structure (to 1.8 A resolution) of the 33-residue leucine zipper portion of the yeast transcription factor GCN4 (4). In fact, the discovery of leucine zippers has led to the rediscovery of coiled coils! We can now see in marvelous detail the physical basis for many of the inferences about coiled-coil structure drawn from low-resolution x-ray crystallographic structures (5), sequence analysis, and model-building of proteins such as tropomyosin and myosin (6). Subsequently other high-resolution structures of coiled-coil proteins-both native and designed-have become available, and these too are enabling us to improve current predictive methods. The first step in predicting coiled coils from sequence is to localize the coiled-coil regions in the sequences-by visual inspec-