Co-evolution of RNA polymerase with RbpA in the phylum Actinobacteria

Publication date: 1 December 2012 Source:Applied & Translational Genomics, Volume 1 Author(s): Abhinav Dey , V.R. Adithi , Dipankar Chatterji The role of RbpA in the backdrop of M. smegmatis showed that it rescues mycobacterial RNA polymerase from rifampicin-mediated inhibition (Dey et al., 2010; Dey et al., 2011). Paget and co-workers (Paget et al., 2001; Newell et al., 2006) have revealed that RbpA homologs occur exclusively in actinobacteria. Newell et al. (2006) showed that MtbRbpA, when complemented in a ∆rbpA mutant of S. coelicolor, showed a low recovery of MIC (from 0.75 to 2μg/ml) as compared to complementation by native RbpA of S. coelicolor (MIC increases from 0.75 to 11μg/ml). Our studies on MsRbpA show that it is a differential marker for M. smegmatis RNA polymerase as compared to E. coli RNA polymerase at IC50 levels of rifampicin. A recent sequence-based analysis by Lane and Darst (2010) has shown that RNA polymerases from Proteobacteria and Actinobacteria have had a divergent evolution. E. coli is a representative of Proteobacteria and M. smegmatis is an Actinobacterium. RbpA has an exclusive occurrence in Actinobacteria. Since protein–protein interactions might not be conserved across different species, therefore, the probable reason for the indifference of MsRbpA toward E. coli RNA polymerase could be the lineage-specific differences between actinobacterial and proteobacterial RNA polymerases. These observations led us to ask the questio...
Source: Applied and Translational Genomics - Category: Genetics & Stem Cells Source Type: research