Mapping the domain structure of Ribonuclease E in Mycobacterium smegmatis

Mycobacterium tuberculosis is a bacterium that causes tuberculosis. Regulation of gene expression and mRNA degradation is important for the ability of the bacteria to survive the stressors of infection. A multiprotein complex called the degradosome is important for mRNA degradation in better-studied bacteria such as E. coli, where Ribonuclease E (RNase E) cleaves mRNA into fragments while using a scaffold domain to interact with other proteins involved in mRNA degradation. We used M. smegmatis, a non-pathogen relative of M. tuberculosis, as a model to define the putative scaffold domains of mycobacterial RNase E. Our results suggest that RNase E has two scaffold domains flanking a putative catalytic domain 493 amino acids in length.