Arginine 37 of Glycine Linker Dictates Regulatory Function of HapR

Frontiers in Microbiology

Abhisek Mondal¹  Saumen Datta¹  Richa Singh²  Saumya Raychaudhuri²  Manjula Ekka²  Himanshu Sen² 

[1] Council of Scientific and Industrial Research (CSIR), Indian Institute of Chemical Biology, Kolkata, India;Council of Scientific and Industrial Research (CSIR), Institute of Microbial Technology, Chandigarh, India;

关键词: HapR;    Vibrio cholerae;    quorum sensing;    linker;    arginine;    DNA binding;   

DOI  :  10.3389/fmicb.2020.01949

来源: DOAJ

【 摘 要 】

HapR is designated as a high cell density quorum sensing master regulatory protein of Vibrio cholerae. It is a member of the TetR family protein and functions both as an activator and a repressor by directly communicating with cognate promoters, thus controlling the expression of a plethora of genes in a density-dependent manner. Molecular insights reveal the domain architecture and further unveil the significance of a cross talk between the DNA binding domain and the dimerization domain for the functionality of the wild-type protein. The DNA binding domain is made up of three α-helices, where a helix-turn-helix motif spans between the helices α2 and α3. The essentiality of the glycine-rich linker linking helices α1 and α2 came into prominence while unraveling the molecular basis of a natural non-functional variant of HapR. Subsequently, the importance of linker length was demonstrated. The present study, involving a series of biochemical analyses coupled with molecular dynamics simulation, has illustrated the indispensability of a critical arginine within the linker at position 37 contributing to HapR–DNA binding activity.

【 授权许可】

Unknown