Specific structural elements of the T-box riboswitch drive the two-step binding of the tRNA ligand.

ABSTRACT: T-box riboswitches are cis-regulatory RNA elements that regulate the expression of proteins involved in amino acid biosynthesis and transport by binding to specific tRNAs and sensing their aminoacylation state. While the T-box modular structural elements that recognize different parts of a tRNA have been identified, the kinetic trajectory describing how these interactions are established temporally remains unclear. Using smFRET, we demonstrate that tRNA binds to the riboswitch in two steps, first anticodon recognition followed by the sensing of the 3' NCCA end, with the second step accompanied by a T-box riboswitch conformational change. Studies on site-specific mutants highlight that specific T-box structural elements drive the two-step binding process in a modular fashion. Our res

SUBMITTER: Zhang J 

PROVIDER: S-EPMC6197855 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature