Function prediction of Rv0079, a hypothetical Mycobacterium tuberculosis DosR regulon protein.

Mycobacterium tuberculosis (Mtb), the pathogen causing tuberculosis, continues to elude a cure. Latent Mtb forms are present in human population for extended periods and have the potential to be re-activated into an active form. The prophylactic vaccine, live-attenuated Mycobacterium bovis Bacillus-Calmette-Guerin (BCG) vaccine is not effective in preventing latent infection. The failure of BCG in prevention/protection against latent forms of Mtb calls for efforts to curb latent Mtb infection. The inclusion of latency/dormancy antigens in the classical antigen preparation is surmised as a strategy. DosR (Dormancy Survival Regulator, Rv3133c) regulon genes are expressed under the conditions of latency/dormancy. Previous bioinformatics analyses have pointed towards their role as probable vaccine candidates. Since nearly 60% of DosR regulon genes are unannotated, efforts towards elucidating their functional role will prove valuable. The study presented here provides an in-depth in silico 3D-structure prediction and functional analyses of the first member of the DosR regulon group, the hypothetical protein, Rv0079. A combination of approaches such as: homology modeling and threading using SWISS-MODEL workspace, Phyre and BioInfo bank Metaserver; protein localization predictions using PSORTb, LOCtree, TMHMM and TMpred; function prediction using ProFunc, epitope prediction using NetCTL and others was implemented. Evidence gathered from a combination of bioinformatics tools supports the hypothesis that Mtb Rv0079 protein is a likely cytoplasmic translation factor. Experimental validation will help provide more insight into its actual function.