A tRNA modification inMycobacterium tuberculosisfacilitates optimal intracellular growth

Abstract

Diverse chemical modifications fine-tune the function and metabolism of tRNA. Although tRNA modification is universal in all kingdoms of life, profiles of modifications, their functions, and physiological roles have not been elucidated in most organisms including the human pathogen,Mycobacterium tuberculosis(Mtb), the causative agent of tuberculosis. To identify physiologically important modifications, we surveyed the tRNA ofMtb, using tRNA sequencing (tRNA-seq) and genome-mining. Homology searches identified 18 candidate tRNA modifying enzymes that are predicted to create 13 tRNA modifications across all tRNA species. Reverse transcription-derived error signatures in tRNA-seq predicted the sites and presence of 9 modifications. Several chemical treatments prior to tRNA-seq expanded the number of predictable modifications. Deletion ofMtbgenes encoding two modifying enzymes, TruB and MnmA, eliminated their respective tRNA modifications, validating the presence of modified sites in tRNA species. Furthermore, the absence ofmnmAattenuatedMtbgrowth in macrophages, suggesting that MnmA-dependent tRNA uridine sulfation contributes toMtbintracellular growth. Our results lay the foundation for unveiling the roles of tRNA modifications inMtbpathogenesis and developing new therapeutics against tuberculosis.

Mapping the tRNA Modification Landscape ofBartonella henselaeHouston I andBartonella quintanaToulouse

“…Advancing our understanding requires the integration of analytical tools such as mass spectrometry (MS) or next-generation sequencing with comparative genomic analyses across diverse organisms spanning the tree of life 5 . Recent years have seen integrated studies that successfully cataloged tRNA modifications and associated genes in a few pathogenic bacteria, such as Vibrio cholerae 12 and Mycobacterium tuberculosis 13 , as well as in the antibiotic-producing Streptomyces albidoflavus 14 . Notably absent from these investigations are members of obligate intracellular bacterial families like Chlamydiaceae , Rickettsiaceae , or Ehrlichiaceae which harbor significant pathogenic species for humans 15,16 .…”