Allosteric activation of HutP protein, that regulates transcription of hut operon in Bacillus subtilis, mediated by various analogs of histidine

HutP is an RNA-binding protein which regulates the expression of the histidine utilization (hut) operon in Bacillus subtilis by binding to cis-acting regulatory sequences on the hut mRNA in the presence of L-histidine. In the case of HutP-RNA interactions, L-histidine plays an allosteric activation role i.e. only the activated HutP specifically recognize the hut mRNA. In the present study, we analyzed various analogs of L-histidine to evaluate the important functional groups of L-histidine that is responsible for the activation of HutP. Our analysis clearly suggests that imidazole group of a L-histidine plays a vital role for the activation. Our analysis also revealed efficient analogs of L-histidine for the activation, for example, L-histidine beta-naphthylamide and L-Histidine benzyl ester.