Insights into metalloregulation by M-box riboswitch RNAs via structural analysis of manganese-bound complexes.

ABSTRACT: The M-box riboswitch couples intracellular magnesium levels to expression of bacterial metal transport genes. Structural analyses on other riboswitch RNA classes, which typically respond to a small organic metabolite, have revealed that ligand recognition occurs through a combination of base-stacking, electrostatic, and hydrogen-bonding interactions. In contrast, the M-box RNA triggers a change in gene expression upon association with an undefined population of metals, rather than responding to only a single ligand. Prior biophysical experimentation suggested that divalent ions associate with the M-box RNA to promote a compacted tertiary conformation, resulting in sequestration of a short sequence tract otherwise required for downstream gene expression. Electrostatic shielding from loosely

SUBMITTER: Ramesh A 

PROVIDER: S-EPMC3056551 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature