Acquisition of a stable structure by yeast ribosomal PO protein requires binding of P1A-P2B complex:: In vitro formation of the stalk structure
Acquisition of a stable structure by yeast ribosomal PO protein requires binding of P1A-P2B complex:: In vitro formation of the stalk structure
复制标题
DOI：
10.1016/j.bbagen.2005.03.009
复制
发表时间：
2005-06-20
影响因子：
3
通讯作者：
Grankowski, N
中科院分区：
文献类型：
--
作者：
Krokowski, D;Tchórzewski, M;Grankowski, N
酿酒酵母核糖体柄由5种蛋白组成：分子质量为34 kDa的P0蛋白和4种较小的酸性蛋白，分别为11kDa、P1A、P11B、P2A和P2B，它们组成了一个五聚体复合物P0-(P1A-P2B)/(P1B-P2A)。该结构与26S rRNA的gtpase相关区域结合，在蛋白质合成中起着至关重要的作用。导致茎结构形成的连续步骤尚未完全阐明，单个p蛋白在茎组装和蛋白质合成中的功能仍然难以捉摸。我们应用了一种综合的方法来检查所有的p蛋白与茎组装。几种体外方法被用来模拟细胞中的蛋白质自组织。我们的努力使整个重组茎秆在溶液中以及在核糖体颗粒上重组。根据我们的分析，可以推断PIA-M蛋白复合物可能是茎秆形成的关键元件，具有结构和功能上的重要性，而P1B-P2A蛋白复合物则参与调控茎秆功能。四元结构形成的机制可以描述为低聚体系与P0-(P1A-P2B)蛋白复合物的连续共折叠/结合反应，这是获得核糖体茎稳定的四元结构的必要因素。另一方面，P1B-P2A复合体不参与协同茎的形成，我们的研究结果表明，由于后一种蛋白质对，蛋白质合成速率增加。(c) 2005 Elsevier B.V.版权所有
Saccharomyces cerevisiae ribosomal stalk consists of five proteins: P0 protein, with molecular mass of 34 kDa, and four small, 11kDa, P1A, P11B, P2A and P2B acidic proteins, which form a pentameric complex P0-(P1A-P2B)/(P1B-P2A). This structure binds to a region of 26S rRNA termed GTPase-associated domain and plays a crucial role in protein synthesis. The consecutive steps leading to the formation of the stalk structure have not been fully elucidated and the function of individual P-proteins in the assembling of the stalk and protein synthesis still remains elusive. We applied an integrated approach in order to examine all the P-proteins with respect to stalk assembly. Several in vitro methods were utilized to mimic protein self-organization in the cell. Our efforts resulted in reconstitution of the whole recombinant stalk in solution as well as on the ribosomal particle. On the basis of our analysis, it can be inferred that the PIA-M protein complex may be regarded as the key element in stalk formation, having structural and functional importance, whereas P1B-P2A protein complex is implicated in regulation of stalk function. The mechanism of quaternary structure formation could be described as a sequential co-folding/ association reaction of an oligomeric system with P0-(P1A-P2B) protein complex as an essential element in the acquisition of a stable quaternary structure of the ribosomal stalk. On the other hand, the P1B-P2A complex is not involved in the cooperative stalk formation and our results indicate an increased rate of protein synthesis due to the latter protein pair. (c) 2005 Elsevier B.V. All rights reserved.