Structural characterizations of metal ion binding transcriptional regulator CueR from opportunistic pathogen pseudomonas aeruginosa to identify its possible involvements in virulence.

Pseudomonas aeruginosa is an opportunistic pathogen present in the environment. It is responsible behind a variety of diseases specifically the multidrug-resistant nosocomial infections and chronic lung infections in cystic fibrosis patients. One of the vital genes of the organism responsible for its multidrug-resistant behavior is the gene PA3523 which codes for the multidrug efflux transporter. The expression of PA3523 is regulated by the dimeric transcription factor CueR having helix-turn-helix DNA binding motif. So far, there have been no previous reports that depict the characterization of CueR protein from P. aeruginosa from a structural point of view. In the present work, an attempt has been made to characterize CueR protein by structural bioinformatics approach. The dimeric structure of CueR was built by comparative modeling technique. The dimeric model of CueR was then docked onto the corresponding promoter region of the PA3523 gene encoding the multidrug efflux transporter. The docked complex of promoter DNA with CueR protein was subjected to molecular dynamics simulations to identify the mode of DNA-protein interactions. So far, this is the first report that depicts the mechanistic details of gene regulation by CueR protein. This work may therefore be useful to illuminate the still obscure molecular mechanism behind disease propagation by P. aeruginosa.