Arginine 37 of Glycine Linker Dictates Regulatory Function of HapR.

ABSTRACT: 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 ?-helices, where a helix-turn-helix motif spans between the helices ?2 and ?3. The essentiality of the glycine-rich linker linking helices ?1 and ?2 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.

SUBMITTER: Ekka M 

PROVIDER: S-EPMC7472637 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature