title: The essential mycobacterial amidotransferase GatCAB is a modulator of specific translational fidelity.
abstract: Although regulation of translation fidelity is an essential process1-7, diverse organisms and organelles have differing requirements of translational accuracy8-15, and errors in gene translation serve an adaptive function under certain conditions16-20. Therefore, optimal levels of fidelity may vary according to context. Most bacteria utilize a two-step pathway for the specific synthesis of aminoacylated glutamine and/or asparagine tRNAs, involving the glutamine amidotransferase GatCAB21-25, but it had not been appreciated that GatCAB may play a role in modulating mistranslation rates. Here, by using a forward genetic screen, we show that the mycobacterial GatCAB enzyme complex mediates the translational fidelity of glutamine and asparagine codons. We identify mutations in gatA that cause partial loss of function in the holoenzyme, with a consequent increase in rates of mistranslation. By monitoring single-cell transcription dynamics, we demonstrate that reduced gatCAB expression leads to increased mistranslation rates, which result in enhanced rifampicin-specific phenotypic resistance. Consistent with this, strains with mutations in gatA from clinical isolates of Mycobacterium tuberculosis show increased mistranslation, with associated antibiotic tolerance, suggesting a role for mistranslation as an adaptive strategy in tuberculosis. Together, our findings demonstrate a potential role for the indirect tRNA aminoacylation pathway in regulating translational fidelity and adaptive mistranslation.
authors: Collaboration Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, School of Medicine, Tsinghua University, Beijing 100084, China.
authors: Hong-Wei
authors: HW
authors: Su
authors: Collaboration Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, School of Medicine, Tsinghua University, Beijing 100084, China.|School of Life Sciences, Peking University, Beijing 10087, China.
authors: Jun-Hao
authors: JH
authors: Zhu
authors: Collaboration Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, School of Medicine, Tsinghua University, Beijing 100084, China.
authors: Hao
authors: H
authors: Li
authors: Collaboration Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, School of Medicine, Tsinghua University, Beijing 100084, China.
authors: Rong-Jun
authors: RJ
authors: Cai
authors: Faculty of Health Sciences, DST/NRF Centre of Excellence for Biomedical TB Research, University of the Witwatersrand, National Health Laboratory Service, Johannesburg 2193, South Africa.
authors: Christopher
authors: C
authors: Ealand
authors: Collaboration Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, School of Medicine, Tsinghua University, Beijing 100084, China.
authors: Xun
authors: X
authors: Wang
authors: Collaboration Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, School of Medicine, Tsinghua University, Beijing 100084, China.
authors: Yu-Xiang
authors: YX
authors: Chen
authors: Center for Synthetic and Systems Biology, MOE Key Laboratory of Bioinformatics, Collaboration Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors: Masood Ur Rehman
authors: MU
authors: Kayani
authors: Center for Synthetic and Systems Biology, MOE Key Laboratory of Bioinformatics, Collaboration Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors: Ting F
authors: TF
authors: Zhu
authors: Wellcome Trust Sanger Institute, Hinxton CB10 1SA, UK.
authors: Danesh
authors: D
authors: Moradigaravand
authors: National Clinical Laboratory on Tuberculosis, Beijing Tuberculosis and Thoracic Tumor Institute, Beijing Chest Hospital, Capital Medical University, Beijing 101149, China.
authors: Hairong
authors: H
authors: Huang
authors: Faculty of Health Sciences, DST/NRF Centre of Excellence for Biomedical TB Research, University of the Witwatersrand, National Health Laboratory Service, Johannesburg 2193, South Africa.
authors: Bavesh D
authors: BD
authors: Kana
authors: Collaboration Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, School of Medicine, Tsinghua University, Beijing 100084, China.
authors: Babak
authors: http://orcid.org/0000-0002-6354-6305
authors: B
authors: Javid
mesh_terms: D001216:Asparagine / Q000378:metabolism; D003062:Codon; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005973:Glutamine / Q000378:metabolism; D009154:Mutation; D020102:Mycobacterium smegmatis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D019884:Nitrogenous Group Transferases / Q000235:genetics* / Q000378:metabolism; D014176:Protein Biosynthesis; D012293:Rifampin / Q000494:pharmacology; D046249:Transfer RNA Aminoacylation
chemical_list: D003062:Codon; D005973:Glutamine; D001216:Asparagine; D019884:Nitrogenous Group Transferases; D012293:Rifampin