STRUCTURAL BIOLOGY OF MACROMOLECULAR STRUCTURE

本实验室致力于阐明控制细胞生长的机制 大分子络合物的组装，特别是它们的 功能原理。在过去的一年里，主要的努力是 旨在提高三维密度的分辨率 从低温电子计算的二十面体病毒衣壳图 显微照片。因此，我们将有限的事件定性为 噬菌体HK97主要衣壳蛋白的蛋白降解诱导 稳定衣壳的扩张。删除的域驻留在 六角形和五角形的内表面，它的去除允许 推进成熟化转型进行。这一过渡 有助于形成相邻的共价交联链 亚单位。(2)对牛乳头瘤病毒的分析已扩大 到1纳米以下的分辨率，显示了丰富的细节 关于五聚胶囊的结构，并公开了 微小衣壳蛋白L2的可能位置。(Iii)船壳 由昆虫细胞合成的蛋白质组装的单纯疱疹病毒 来自杆状病毒的表达载体已被发现在结构上 正宗的。12 kDa的VP26蛋白已被证明与主要的 衣壳蛋白VP5仅以其六邻体状态存在，而不以其五元状态存在。 来自ClpAP阴性染色标本的图像分析 能量依赖的蛋白水解酶，亚复合体的低聚性质 已经被定义，他们的互动模式也是如此。ClpP，一种蛋白酶， 由两个七重环和三磷酸腺苷的水解物ClpA组成， 形成六角环。在活性络合物中，它们在轴向堆积，结果 在可能具有相互旋转含义的对称失配中 有动静。角化细胞的组装也取得了进展 终末分化的角质形成细胞的包膜 噬菌体尾部纤维蛋白的组织。

This Laboratory seeks to elucidate the mechanisms that control the assembly of macromolecular complexes, with particular emphasis on their functional rationale. Over the past year, a major effort has been directed towards enhancing the resolution of three-dimensional density maps of icosahedral virus capsids calculated from cryo-electron micrographs. Thus, we have characterized the events whereby limited proteolysis of the major capsid protein of bacteriophage HK97 induces the stabilizing expansion of the capsid. The excised domain resides on the inner surface of the hexons and pentons, and its removal permits the prohead to maturation transformation to proceed. This transition facilitates the formation of covalent cross-links between neighboring subunits. (ii) In bovine papillomavirus, the analysis has been extended to a resolution of better than 1nm, revealing a wealth of detail concerning the structures of the pentameric capsomers, and disclosing the possible location of the minor capsid protein, L2. (iii) Capsids of herpes simplex virus assembled from proteins synthesized in insect cells from baculovirus expression vectors have been found to be structurally authentic. The 12kDa VP26 protein has been shown to bind to the major capsid protein VP5 only in its hexon state, not in its penton state. From image analysis of negatively stained specimens of the ClpAP energy-dependent protease, the oligomeric natures of the subcomplexes have been defined, as has their mode of interaction. ClpP, the protease, consists of two 7-fold rings, and ClpA, the ATP-hydrolyzing component, forms hexameric rings. In active complexes, they stack axially, resulting in a symmetry mismatch that may have connotations of mutual rotational movement. Progress has also been made on the assembly of cornified cell envelopes of terminally differentiated keratinocytes, and on the domainal organization of bacteriophage tail-fiber proteins.