Structure determination of the small ubiquitin-related modifier SUMO-1
Structure determination of the small ubiquitin-related modifier SUMO-1
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DOI：
10.1006/jmbi.1998.1839
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发表时间：
1998-07-10
影响因子：
5.6
通讯作者：
Becker, J
中科院分区：
文献类型：
--
作者：
Bayer, P;Arndt, A;Becker, J
最近发现的小泛素相关修饰素SUMO-1属于不断增长的泛素相关蛋白家族，参与翻译后蛋白质修饰。与泛素不同，SUMO-1似乎不靶向蛋白质降解，但似乎参与蛋白质-蛋白质相互作用的调节。独立的研究表明SUMO-1在调节核质转运中的重要功能，并表明在细胞周期调节和凋亡中的作用。在这里，我们提出了第一个三维结构的SUMO-1解决了NMR。虽然与泛素只有18%的氨基酸序列同一性，但整体结构与泛素非常相似，特征是泛素蛋白家族的β β α β α β折叠。此外，形成异肽键所需的两个C-末端Gly残基的位置在泛素和SUMO-1之间是保守的。SUMO-1最显著的特征是一个长且高度柔性的N末端，其从蛋白质的核心突出，并且在泛素中不存在。此外，产生泛素聚合物所需的泛素Lys 48在SUMO-1中的相同位置被Gln 69取代，这解释了为什么未观察到SUMO-1形成聚合物。此外，SUMO-1和泛素的疏水核心是由保守的疏水残基维持的，而SUMO-1和泛素的整体电荷拓扑结构显着不同，这表明这两种蛋白质的特定修饰酶和靶蛋白。(C)北京：科学出版社.
The recently discovered small ubiquitin-related modifier SUMO-1 belongs to the growing family of ubiquitin-related proteins involved in postranslational protein modification. Unlike ubiquitin, SUMO-1 does not appear to target proteins for degradation but seems to be involved in the modulation of protein-protein interactions. Independent studies demonstrate an essential function of SUMO-1 in the regulation of nucleo-cytoplasmic transport, and suggest a role in cell-cycle regulation and apoptosis. Here, we present the first three-dimensional structure of SUMO-1 solved by NMR. Although having only 18% amino acid sequence identity with ubiquitin, the overall structure closely resembles that of ubiquitin, featuring the beta beta alpha beta alpha beta fold of the ubiquitin protein family. In addition, the position of the two C-terminal Gly residues required for isopeptide bond formation is conserved between ubiquitin and SUMO-1. The most prominent feature of SUMO-1 is a long and highly flexible N terminus, which protrudes from the core of the protein and which is absent in ubiquitin. Furthermore, ubiquitin Lys48, required to generate ubiquitin polymers, is substituted in SUMO-1 by Gln69 at the same position, which provides an explanation of why SUMO-1 has not been observed to form polymers. Moreover, the hydrophobic core of SUMO-1 and ubiquitin is maintained by conserved hydrophobic residues, whereas the overall charge topology of SUMO-1 and ubiquitin differs significantly, suggesting specific modifying enzymes and target proteins for both proteins. (C) 1998 Academic Press.