ORTHOGONAL PACKING OF BETA-PLEATED SHEETS IN PROTEINS
ORTHOGONAL PACKING OF BETA-PLEATED SHEETS IN PROTEINS
复制标题
DOI：
10.1021/bi00260a009
复制
发表时间：
1982-01-01
期刊：
影响因子：
2.9
通讯作者：
JANIN, J
中科院分区：
文献类型：
--
作者：
CHOTHIA, C;JANIN, J
两类β-片到β-在球状蛋白质中可以区分为片状堆积。两个类都有. beta。通常的右旋扭曲的床单面对面包装。在正交β中-片状填料，不同β的股线方向。床单是90度。彼此之间。扭曲的β这种取向的片具有反互补表面：β中的一对对角相对的角。床单非常接近，其他对角张开分开。在近角处，β.片层通常是共价连接的：是一个β的一部分的链。片通过右手弯曲变成第二β的一部分。床单。该弯曲可以在β处发生。凸起，或在一段具有特征构象的残基上，形成β。弯曲。β之间的接触片材沿着连接闭合拐角的对角线出现。它们涉及大约四分之一的β-折叠残基，并且它们中的三分之二是瓦尔、Ile或Leu。在其他地方，β之间的空间。片层被来自蛋白质其它部分的侧链填充，通常是α。螺旋状的放在张开的角上。正交β-的例子在醇脱氢酶、酸性蛋白酶、胰蛋白酶家族、木瓜蛋白酶、葡萄球菌核酸酶和嗜热菌蛋白酶中发现了片状堆积。在对齐的β中-片状填料，填料β的股线方向之间的角度。sheets是. apprx。30度在这个方向上，扭曲的β-片表面是互补的。控制这类β的原理是：前面描述了片状填料。对齐和正交包装类的差异和相似之处进行了讨论。
Two classes of .beta.-sheet to .beta.-sheet packing can be distinguished in globular proteins. Both classes have .beta. sheets with the usual right-handed twist packed face to face. In orthogonal .beta.-sheet packings, the strand directions of the different .beta. sheets are 90.degree. to each other. Twisted .beta. sheets in this orientation have anticomplementary surfaces: one pair of diagonally opposite corners in the .beta. sheets are very close, and the other pairs of corners splay apart. At the close corners, the .beta. sheets are usually covalently connected: a strand that is part of one .beta. sheet turns through a right-handed bend to become part of the second .beta. sheet. The bend may occur at a .beta. bulge, or over a stretch of residues with a characteristic conformation, forming a .beta. bend. Contacts between the .beta. sheets occur along the diagonal joining the close corners. They involve about one-fourth of the .beta.-sheet residues, and two-thirds of them are Val, Ile, or Leu. Elsewhere, the space between the .beta. sheets is filled by side chains from other parts of the protein, often .alpha. helices placed at the splayed corners. Examples of orthogonal .beta.-sheet packing are found in alcohol dehydrogenase, the acid proteases, the trypsin family, papain, staphylococcal nuclease, and thermolysin. In aligned .beta.-sheet packings, the angle between the strand directions of the packed .beta. sheets is .apprx. 30.degree.. In this orientation, the twisted .beta.-sheet surfaces are complementary. The principles governing this class of .beta.-sheet packings were described previously. The differences and similarities of the aligned and orthogonal packing classes are discussed.