2′-O-methylation in mRNA disrupts tRNA decoding during translation elongation

• Published in: Nature structural & molecular biology Vol. 25; no. 3; pp. 208 - 216
• Main Authors: Choi, Junhong, Indrisiunaite, Gabriele, DeMirci, Hasan, Ieong, Ka-Weng, Wang, Jinfan, Petrov, Alexey, Prabhakar, Arjun, Rechavi, Gideon, Dominissini, Dan, He, Chuan, Ehrenberg, Måns, Puglisi, Joseph D.
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01.03.2018; Nature Publishing Group
• Subjects: 631/535/1266; 631/57/2265; Amino acids; Analysis; Anticodon; BASIC BIOLOGICAL SCIENCES; Biochemistry; Biological Microscopy; Biomedical and Life Sciences; Chemical properties; Chemical synthesis; Codon; Codons; Decoding; Elongation; Elongation factor EF-Tu; Guanosine triphosphate; Helices; Hydrolysis; Life Sciences; Membrane Biology; Messenger RNA; Methylation; mRNA; mRNA processing; Nucleotides; Organic chemistry; Peptide Chain Elongation, Translational; Proofreading; Protein biosynthesis; Protein Structure; Protein synthesis; Proteins; RNA; RNA, Messenger - metabolism; RNA, Transfer - metabolism; RNA, Transfer, Amino Acyl - metabolism; Structure; Transcription; Transfer RNA; Translation; Translation (Genetics); Translation elongation; Translation elongation factors; tRNA; United States
• ISSN: 1545-9993; 1545-9985; 1545-9985
• DOI: 10.1038/s41594-018-0030-z

Chemical modifications of mRNA may regulate many aspects of mRNA processing and protein synthesis. Recently, 2′- O -methylation of nucleotides was identified as a frequent modification in translated regions of human mRNA, showing enrichment in codons for certain amino acids. Here, using single-molecule, bulk kinetics and structural methods, we show that 2′- O -methylation within coding regions of mRNA disrupts key steps in codon reading during cognate tRNA selection. Our results suggest that 2′- O -methylation sterically perturbs interactions of ribosomal-monitoring bases (G530, A1492 and A1493) with cognate codon–anticodon helices, thereby inhibiting downstream GTP hydrolysis by elongation factor Tu (EF-Tu) and A-site tRNA accommodation, leading to excessive rejection of cognate aminoacylated tRNAs in initial selection and proofreading. Our current and prior findings highlight how chemical modifications of mRNA tune the dynamics of protein synthesis at different steps of translation elongation. 2′- O -methylation within mRNA coding regions sterically perturbs interactions of ribosomal-monitoring bases with cognate codon–anticodon helices, leading to excessive rejection of cognate aminoacylated tRNAs during initial selection and proofreading.