Solution NMR determination of hydrogen bonding and base pairing between the glyQS T box riboswitch Specifier domain and the anticodon loop of tRNAGly.

Highlights: [•] A T box riboswitch Specifier domain–tRNA anticodon arm complex was prepared. [•] The complex mirrors ribosomal codon–anticodon pairing with three base pairs. [•] Specifier bases rotate towards the minor groove to engage the tRNA anticodon. [•] The structure of the anticodon loop evolves to adopt a U-turn motif in the complex. [•] Loss of the U-turn reduces affinity but does not prevent complex formation. [ABSTRACT FROM AUTHOR]