PlrA (MSMEG_5223) is an essential polar growth regulator in Mycobacterium smegmatis

Mycobacteria expand their cell walls at the cell poles in a manner that is not well described at the molecular level. In this study, we identify a new factor, PlrA, involved in restricting peptidoglycan metabolism to the cell poles in Mycobacterium smegmatis. We show that PlrA localizes to the pole tips, and we identify its essential domain. We show that depletion of plrA pheno-copies depletion of polar growth factor Wag31, and that PlrA is involved in regulating polar peptidoglycan metabolism and the structure of the Wag31 polar foci.