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The role of Lys2–Cl − –Lys2 salt linkages in oligomeric intermediates of RbsD protein in Escherichia coli
Author(s) -
Zheng Jing,
Zheng Jie,
Ma Yuanwu,
Zuo Guocai,
Feng Yongjun
Publication year - 2020
Publication title -
journal of basic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0233-111X
DOI - 10.1002/jobm.201900337
Subject(s) - protein subunit , chemistry , salt (chemistry) , biophysics , protein aggregation , biochemistry , biology , organic chemistry , gene
As a homo‐oligomeric protein, the disassembly of Escherichia coli RbsD 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 of E. coli RbsD 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 with d ‐ribose. On the basis of these results, we suggest that Lys2–Cl − –Lys2 salt linkages in E. coli RbsD 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.