Loss of N1-methylation of G37 in tRNA induces ribosome stalling and reprograms gene expression

eLife

Ya-Ming Hou¹  Thomas Christian¹  Isao Masuda¹  Howard Gamper¹  Sunita Maharjan¹  Fuad Mohammad²  Allen R Buskirk²  Jae-Yeon Hwang² 

[1] Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, United States;Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, United States;

关键词: ribosome profling;    ribosome pausing;    TrmD;    m1G37-tRNA;    stringent response;   

DOI  :  10.7554/eLife.70619

来源: DOAJ

【 摘 要 】

N1-methylation of G37 is required for a subset of tRNAs to maintain the translational reading-frame. While loss of m1G37 increases ribosomal +1 frameshifting, whether it incurs additional translational defects is unknown. Here, we address this question by applying ribosome profiling to gain a genome-wide view of the effects of m1G37 deficiency on protein synthesis. Using E coli as a model, we show that m1G37 deficiency induces ribosome stalling at codons that are normally translated by m1G37-containing tRNAs. Stalling occurs during decoding of affected codons at the ribosomal A site, indicating a distinct mechanism than that of +1 frameshifting, which occurs after the affected codons leave the A site. Enzyme- and cell-based assays show that m1G37 deficiency reduces tRNA aminoacylation and in some cases peptide-bond formation. We observe changes of gene expression in m1G37 deficiency similar to those in the stringent response that is typically induced by deficiency of amino acids. This work demonstrates a previously unrecognized function of m1G37 that emphasizes its role throughout the entire elongation cycle of protein synthesis, providing new insight into its essentiality for bacterial growth and survival.

【 授权许可】

Unknown