The Mycobacterium tuberculosis sRNA F6 modifies expression of essential chaperonins, GroEL2 and GroES

Almost 140 years after the identification of Mycobacterium tuberculosis as the etiological agent of tuberculosis, important aspects of its biology remain poorly described. Little is known about the role of post-transcriptional control of gene expression and RNA biology, including the role of most of the small RNAs (sRNAs) identified to date. We have carried out a detailed investigation of the M. tuberculosis sRNA, F6, and shown it to be dependent on SigF for expression, and significantly induced in starvation conditions in vitro and in a mouse model of infection. Further exploration of F6 using an in vitro starvation model of infection indicates that F6 affects the expression of the essential chaperonins, GroEL2 and GroES. Our results point towards a role for F6 during periods of low metabolic activity typically associated with long-term survival of M. tuberculosis in human granulomas.