Structural basis of a two-step tRNA recognition mechanism for plastid glycyl-tRNA synthetase.

ABSTRACT: Two types of glycyl-tRNA synthetase (GlyRS) are known, the α2 and the α2β2 GlyRSs. Both types of synthetase employ a class II catalytic domain to aminoacylate tRNAGly. In plastids and some bacteria, the α and β subunits are fused and are designated as (αβ)2 GlyRSs. While the tRNA recognition and aminoacylation mechanisms are well understood for α2 GlyRSs, little is known about the mechanisms for α2β2/(αβ)2 GlyRSs. Here we describe structures of the (αβ)2 GlyRS from Oryza sativa chloroplast by itself and in complex with cognate tRNAGly. The set of structures reveals that the U-shaped β half of the synthetase selects the tRNA in a two-step manner. In the first step, the synthetase engages the elbow and the anticodon base C35 of the tRNA. In the second step, the tRNA has rotated ∼9° toward th

SUBMITTER: Yu Z 

PROVIDER: S-EPMC10164559 | biostudies-literature | 2023 May

REPOSITORIES: biostudies-literature