MSMEG_0311 is a conserved essential polar protein involved in mycobacterium cell wall metabolism

Abstract

Cell wall synthesis and cell division are two closely linked pathways in a bacterial cell which distinctly influence the growth and survival of a bacterium. This requires an appreciable coordination between the two processes, more so, in case of mycobacteria with an intricate multi-layered cell wall structure. In this study, we investigated a conserved gene cluster and show that knockdown of most of the genes in this cluster leads to growth defects. We further characterised one of the genes, MSMEG_0311. The repression of this gene not only imparts severe growth defect but also changes colony morphology. We demonstrate that the protein preferentially localises to the polar region and show its influence on the polar growth of the bacillus. A combination of permeability and drug susceptibility assay strongly suggests a cell wall associated function of this gene which is also corroborated by transcriptomic analysis of the knockdown. Considering the gene is highly conserved across mycobacterial species and appears to be essential for growth, it may serve as a potential drug target.