Crystal structure of the human ubiquitin-like protein NEDD8 and interactions with ubiquitin pathway enzymes
Crystal structure of the human ubiquitin-like protein NEDD8 and interactions with ubiquitin pathway enzymes
复制标题
DOI：
10.1074/jbc.273.52.34983
复制
发表时间：
1998-12-25
影响因子：
4.8
通讯作者：
Hill, CP
中科院分区：
文献类型：
--
作者：
Whitby, FG;Xia, G;Hill, CP
NEDD 8/Rub 1类泛素样蛋白参与细胞周期从G（1）期进入S期的进程。这些分子经历与泛素平行的代谢，并涉及与许多不同蛋白质的特异性相互作用。我们在这里报告的重组人NEDD 8的晶体结构，在1.6埃分辨率的R因子为21.9%。正如预期的那样，（57%相同），NEDD 8结构非常类似于先前报道的泛素。我们还表明重组人NEDD 8蛋白被泛素激活（El）酶激活，尽管效率低下，并且NEDD 8可以从El转移到泛素缀合酶E2- 25 K，E2- 25 K将NEDD 8以与泛素相似的效率添加到多聚泛素链上。由三个泛素和一个组氨酸标记的NEDD 8组成的嵌合四聚体以与四泛素相似的亲和力结合26 S蛋白酶体。与泛素中的相应残基不同但在NEDD 8直系同源物之间保守的七个残基是介导与NEDD 8特异性伴侣相互作用的候选者。一个这样的残基，Ala-72（泛素中的Arg），显示在选择与泛素El酶的反应中起关键作用，从而防止NEDD 8不适当地转移到泛素特异性途径中。
The NEDD8/Rub1 class of ubiquitin-like proteins has been implicated in progression of the cell cycle from G(1) into S phase. These molecules undergo a metabolism that parallels that of ubiquitin and involves specific interactions with many different proteins. We report here the crystal structure of recombinant human NEDD8 refined at 1.6-Angstrom resolution to an R factor of 21.9%. As expected from the high sequence similarity (57% identical), the NEDD8 structure closely resembles that reported previously for ubiquitin, We also show that recombinant human NEDD8 protein is activated, albeit inefficiently, by the ubiquitin-activating (El) enzyme and that NEDD8 can be transferred from El to the ubiquitin conjugating enzyme E2-25K, E2-25K adds NEDD8 to a polyubiquitin chain with an efficiency similar to that of ubiquitin, A chimeric tetramer composed of three ubiquitins and one histidine-tagged NEDD8 binds to the 26 S proteasome with an affinity similar to that of tetraubiquitin. Seven residues that differ from the corresponding residues in ubiquitin, but are conserved between NEDD8 orthologs, are candidates for mediating interactions with NEDD8-specific partners. One such residue, Ala-72 (Arg in ubiquitin), is shown to perform a key role in selecting against reaction with the ubiquitin El enzyme, thereby acting to prevent the inappropriate diversion of NEDD8 into ubiquitin-specific pathways.