Tautomeric G•U pairs within the molecular ribosomal grip and fidelity of decoding in bacteria.

ABSTRACT: We report new crystallographic structures of Thermus thermophilus ribosomes complexed with long mRNAs and native Escherichia coli tRNAs. They complete the full set of combinations of Watson-Crick G•C and miscoding G•U pairs at the first two positions of the codon-anticodon duplex in ribosome functional complexes. Within the tight decoding center, miscoding G•U pairs occur, in all combinations, with a non-wobble geometry structurally indistinguishable from classical coding Watson-Crick pairs at the same first two positions. The contacts with the ribosomal grip surrounding the decoding center are all quasi-identical, except in the crowded environment of the amino group of a guanosine at the second position; in which case a G in the codons may be preferred. In vivo experimental data show that

SUBMITTER: Rozov A 

PROVIDER: S-EPMC6101523 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature