Mapping the tRNA Modification Landscape ofBartonella henselaeHouston I andBartonella quintanaToulouse

Abstract

AbstractTransfer RNA (tRNA) modifications play a crucial role in maintaining translational fidelity and efficiency, and they may function as regulatory elements in stress response and virulence. Despite their pivotal roles, a comprehensive mapping of tRNA modifications and their associated synthesis genes is still limited, with a predominant focus on free-living bacteria. In this study, we employed a multidisciplinary approach, incorporating comparative genomics, mass spectrometry, and next-generation sequencing, to predict the set of tRNA modification genes responsible for tRNA maturation in two intracellular pathogens—Bartonella henselaeHouston I andBartonella quintanaToulouse, which are causative agents of cat-scratch disease and trench fever, respectively. This analysis presented challenges, particularly because of host RNA contamination, which served as a potential source of error. However, our approach predicted 26 genes responsible for synthesizing 23 distinct tRNA modifications inB. henselaeand 22 genes associated with 23 modifications inB. quintana. Notably, akin to other intracellular and symbiotic bacteria, bothBartonellaspecies have undergone substantial reductions in tRNA modification genes, mostly by simplifying the hypermodifications present at positions 34 and 37.B. quintanaexhibited the additional loss of four modifications and these were linked to examples of gene decay, providing snapshots of reductive evolution.