The role of Lys2-Cl− -Lys2 salt linkages in oligomeric intermediates of RbsD protein in Escherichia coli
The role of Lys2-Cl− -Lys2 salt linkages in oligomeric intermediates of RbsD protein in Escherichia coli
复制标题
Lys2-Cl-Lys2 盐键在大肠杆菌 RbsD 蛋白寡聚中间体中的作用
DOI：
10.1002/jobm.201900337
复制
发表时间：
2019
影响因子：
3.1
通讯作者：
Yongjun Feng
中科院分区：
文献类型：
--
作者：
Jing Zheng;Jie Zheng;Yuanwu Ma;Guocai Zuo;Yongjun Feng
作为一种同源低聚蛋白，Escherichia coliRbsD Decamer的分解产生了尿素未折叠的寡聚中间结构，因为该蛋白的解离速度慢于去折叠过程。有5个Lys2-Cl−-lys2盐键连接这些亚基。为了探索盐键在这些低聚中间体中的作用，在E的N端突变了Lys2Ala。设计了ColiRbsD蛋白亚基。研究发现，RbsD突变蛋白(RbsD：K2a)失去了存在于RbsD中的较小的较大寡聚体，并表现出其他几种低聚状态(小于十聚体)，同时低聚体的状态取决于蛋白质的浓度。与RbsD相比，RbsD：K2a亚基的交联能力较弱，而二聚体的交联率较高，RbsD：K2a与d-核糖结合时需要大幅度调整其构象以满足空间要求。在这些结果的基础上，我们认为Lys2-Cl−-lys2是盐键。ColiRbsD蛋白在稳定寡聚体中间产物和维持寡聚体中间产物之间的相互作用中起着重要作用，这可能为这些寡聚体蛋白的研究提供线索。
As a homo‐oligomeric protein, the disassembly ofEscherichia coliRbsD decamer produces a urea‐unfolded oligomeric intermediate structure, as the dissociation speed of the protein is lower than that of the unfolding process. There are five Lys2–Cl−–Lys2 salt linkages to connect these subunits. To explore the role of the salt linkages in these oligomeric intermediates, the Lys2Ala mutated in the N‐terminal ofE. coliRbsD protein subunit was designed. It was found that the RbsD mutation protein (RbsD:K2A) loses its minor larger oligomers, which exist in RbsD, and displays other several oligomeric states (less than decamers), meanwhile the state of the oligomers depends on the protein concentration. It was also found that compared with RbsD, the crosslinking capability of the subunits of RbsD:K2A is weaker, while the crosslinking rate of dimers is higher, RbsD:K2A needs to substantially adjust its conformation to meet the space requirements when combined withd‐ribose. On the basis of these results, we suggest that Lys2–Cl−–Lys2 salt linkages inE. coliRbsD protein play an important role in stabilizing the intermediate products of oligomers and maintaining interaction between the intermediate products of oligomers, which may shed light on the study of these oligomeric proteins.