Domain analysis of the Edwardsiella tarda ferric uptake regulator

The Journal of General and Applied Microbiology

Kun Sun¹  Fang Wang¹  Shuang Cheng¹  Li Sun¹ 

[1] Institute of Oceanology, Chinese Academy of Sciences

关键词: domain swapping;    Edwardsiella tarda;    ferric uptake regulator;    mutagenesis;   

DOI  :  10.2323/jgam.55.351

学科分类：微生物学和免疫学

来源: Applied Microbiology, Molecular and Cellulrar Biosciences Research Foundation

【 摘 要 】

Recent studies have shown that the ferric uptake regulator (Fur) of Edwardsiella tarda (FurEt) shares high sequence identity with the Escherichia coli Fur (FurEc) at the N-terminal DNA-binding region. In the present study, the functional importance of the C-terminal region of FurEt was investigated. It was found that FurEt bearing deletion of the C-terminal 12 residues still possesses most of the repressor activity, whereas FurEt bearing deletions of the C-terminal 16 and more than 16 residues are severely affected in activity. Domain swapping analyses indicated that the chimeric Fur proteins (Et75Ec73 and Et75Vh74) consisting of the N-terminal 1-75 region of FurEt fused to the C-terminal 76-148 region of FurEc and the C-terminal 76-149 region of the Vibrio harveyi Fur (FurVh), respectively, are fully active. C92 of FurEc and C137 of FurVh, which are functionally essential in FurEc and FurVh, respectively, are also essential in Et75Ec73 and Et75Vh74, respectively. Further study identified an artificial Fur protein, EtMF54, which is composed of the N-terminal 49 residues of FurEt and five artificial residues. Compared to FurEt, EtMF54 possesses partial Fur activity that is iron-dependent. These results (i) indicate that there exist certain functional/structural compatibilities among FurEt, FurEc, and FurVh at the C-terminal region; (ii) provide insights to the potential location of the regulatory ion-binding site of FurEt.

【 授权许可】

Unknown