1. Structural insights into mRNA reading frame regulation by tRNA modification and slippery codon-anticodon pairing.
- Author
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Hoffer ED, Hong S, Sunita S, Maehigashi T, Gonzalez RL Jnr, Whitford PC, and Dunham CM
- Subjects
- Escherichia coli metabolism, RNA, Messenger metabolism, RNA, Transfer genetics, RNA, Transfer metabolism, Ribosomes metabolism, Anticodon metabolism, Codon metabolism, Escherichia coli genetics, Gene Expression Regulation, Bacterial, RNA, Messenger genetics, Reading Frames genetics
- Abstract
Modifications in the tRNA anticodon loop, adjacent to the three-nucleotide anticodon, influence translation fidelity by stabilizing the tRNA to allow for accurate reading of the mRNA genetic code. One example is the N1-methylguanosine modification at guanine nucleotide 37 (m
1 G37) located in the anticodon loop andimmediately adjacent to the anticodon nucleotides 34, 35, 36. The absence of m1 G37 in tRNAPro causes +1 frameshifting on polynucleotide, slippery codons. Here, we report structures of the bacterial ribosome containing tRNAPro bound to either cognate or slippery codons to determine how the m1 G37 modification prevents mRNA frameshifting. The structures reveal that certain codon-anticodon contexts and the lack of m1 G37 destabilize interactions of tRNAPro with the P site of the ribosome, causing large conformational changes typically only seen during EF-G-mediated translocation of the mRNA-tRNA pairs. These studies provide molecular insights into how m1 G37 stabilizes the interactions of tRNAPro with the ribosome in the context of a slippery mRNA codon., Competing Interests: EH, SH, SS, TM, RG, PW, CD No competing interests declared, (© 2020, Hoffer et al.)- Published
- 2020
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