Protofilaments and rings, two conformations of the tubulin family conserved from bacterial FtsZ to alpha/beta and gamma tubulin.
Protofilaments and rings, two conformations of the tubulin family conserved from bacterial FtsZ to alpha/beta and gamma tubulin.
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DOI：
10.1083/jcb.135.1.5
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发表时间：
1996-10
期刊：
影响因子：
--
通讯作者：
Stoffler D
中科院分区：
文献类型：
--
作者：
Erickson HP;Stoffler D
HE 微管蛋白家族现在包括 a- 和 13- 微管蛋白，它们是真核微管的主要亚基；-y-微管蛋白，使这些微管成核并在负端调节其动态 (11, 17)；和 FtsZ，微管蛋白的原核同源物，是细菌细胞分裂中的主要细胞骨架蛋白 (5)。两个新成员，~-和 e-微管蛋白，已从数据库中的序列推断出来 (2)。 a/13-微管蛋白和 FtsZ (6) 都组装成直的原丝，可以进一步结合形成二维 (2-D) 1 原丝片。两种类型的原丝也可以采用弯曲构象，形成小环或螺旋。最近发现-/微管蛋白也形成小螺旋(16,17,25)，微管蛋白环家族得到了扩展。我们在这里提出，原丝和环都是由微管蛋白家族的所有成员形成的，并且它们在整个家族中在结构上是同源的。这激发了关于 y 微管蛋白环如何使微管组装成核的新模型。
HE tubulin family now includes a-and 13-tubulin, which are the main subunits of eukaryotic microtubules;-y-tubulin, which nucleates these microtubules and regulates their dynamics at the minus end (11, 17); and FtsZ, a prokaryotic homolog of the tubulins that is the major cytoskeletal protein in bacterial cell division (5). Two new members,~-and e-tubulin, have been inferred from sequences in databases (2). Both a/13-tubulin and FtsZ (6) assemble into straight protofilaments that can associate further to make two-dimensional (2-D) 1 protofilament sheets. Both types of protofilaments can also adopt a curved conformation, forming small rings or spirals. The family of tubulin rings was extended recently by the discovery that-/tubulin also forms small spirals (16, 17, 25). We propose here that both protofilaments and rings are formed by all members of the tubulin family, and that they are structurally homologous across the family. This inspires a new model for how" y-tubulin rings might nucleate microtubule assembly.