Coiled coil domains: Stability, specificity, and biological implications
Coiled coil domains: Stability, specificity, and biological implications
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DOI：
10.1002/cbic.200300781
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发表时间：
2004-02-06
期刊：
影响因子：
3.2
通讯作者：
Arndt, KM
中科院分区：
文献类型：
--
作者：
Mason, JM;Arndt, KM
盘绕线圈是一种常见的结构基序，由蛋白质中约3±5%的氨基酸组成通常，它由两到五个相互缠绕成左旋螺旋的a螺旋组成，形成一个超级线圈。常规的a型螺旋每转一圈要经过3.6个残基，而在左旋螺旋中施加在每个螺旋上的扭曲使这个值降低到3.5左右。这样，螺旋每转两圈就会出现一个七重体。[2,3]克里克于1953年首次描述了卷曲的线圈他指出，a型螺旋排列在一起，远离平行，同时相互缠绕，其侧链以旋钮插入孔的方式排列。同年，Pauling和Corey提出了a-角蛋白的模型大约20年后，兔骨骼原肌球蛋白的序列才被发表，直到20年后，亮氨酸拉链基序的第一个结构才被Alber和他的同事们解开最近的这些发现使盘绕线圈领域成为人们关注的焦点，因为它们明显存在于涉及转录控制等关键相互作用的重要结构中。最常见的观察类型的盘绕线圈是左手；在这里，每个螺旋都有7个周期（七次重复），从两个（在设计的螺旋中）[8]到200个这样的重复在蛋白质中这种重复通常在一个螺旋中表示为（abcdefg） n，在另一个螺旋中表示为（a'-b'-c'-d'-e'-f'-g'） n（图1）。在该模型中，a和d是在两个螺旋界面上发现的典型的非极性核心残基，而e和g是溶剂暴露的极性残基，通过静电相互作用在两个螺旋之间提供特异性。类似地，在右旋线圈中，观察到11个残基重复（非空重复）。[10,11]结构的明显简单性及其七轴周期性引起了广泛的研究。在这里，我们的目标是概述单个氨基酸在维持单个螺旋结构（分子内相互作用）方面的重要性，同时促进正确寡聚态和取向的特定线圈相互作用（分子间相互作用）。
The coiled coil is a common structural motif, formed by approximately 3±5% of all amino acids in proteins.[1] Typically, it consists of two to five a-helices wrapped around each other into a left-handed helix to form a supercoil. Whereas regular a-helices go through 3.6 residues for each complete turn of the helix, the distortion imposed upon each helix within a left-handed coiled coil lowers this value to around 3.5. Thus a heptad repeat occurs every two turns of the helix.[2, 3] The coiled coil was first described by Crick in 1953.[4] He noted that a-helices pack together 208 away from parallel whilst wrapping around each other, with their side chains packing™ in a knobs-into-holes manner∫. The same year, Pauling and Corey put forward a model for a-keratin.[5] It was some 20 years later that the sequence of rabbit skeletal tropomyosin was published,[6] and another twenty until the first structure of the leucine zipper motif was solved by Alber and co-workers.[7] These last discoveries pushed the coiled-coil field into the spotlight, as it became apparent that they are found in important structures that are involved in crucial interactions such as transcriptional control. The most commonly observed type of coiled coil is left-handed; here each helix has a periodicity of seven (a heptad repeat), with anywhere from two (in designed coiled coils)[8] to 200 of these repeats in a protein.[9] This repeat is usually denoted (abcdefg) n in one helix, and (a'-b'-c'-d'-e'-f'-g') n in the other (Figure 1). In this model, a and d are typically nonpolar core residues found at the interface of the two helices, whereas e and g are solventexposed, polar residues that give specificity between the two helices through electrostatic interactions. Similarly in righthanded coiled coils, an eleven-residue repeat is observed (undecatad repeat).[10, 11] The apparent simplicity of the structure with its heptad periodicity has led to extensive studies. Here we aim to outline the importance of individual amino acids in maintaining a-helical structure (intramolecular interactions) within individual helices, whilst promoting specific coiled-coil interactions (intermolecular interactions) of correct oligomeric state and orientation.