A functional genetic screen reveals sequence preferences within a key tertiary interaction in cobalamin riboswitches required for ligand selectivity.

ABSTRACT: Riboswitches are structured mRNA sequences that regulate gene expression by directly binding intracellular metabolites. Generating the appropriate regulatory response requires the RNA rapidly and stably acquire higher-order structure to form the binding pocket, bind the appropriate effector molecule and undergo a structural transition to inform the expression machinery. These requirements place riboswitches under strong kinetic constraints, likely restricting the sequence space accessible by recurrent structural modules such as the kink turn and the T-loop. Class-II cobalamin riboswitches contain two T-loop modules: one directing global folding of the RNA and another buttressing the ligand binding pocket. While the T-loop module directing folding is highly conserved, the T-loop associated

SUBMITTER: Polaski JT 

PROVIDER: S-EPMC6158498 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature