The t(6)A modification acts as a positive determinant for the anticodon nuclease PrrC, and is distinctively nonessential in Streptococcus mutans Journal Article


Authors: Bacusmo, J. M.; Orsini, S. S.; Hu, J.; DeMott, M.; Thiaville, P. C.; Elfarash, A.; Paulines, M. J.; Rojas-Benítez, D.; Meineke, B.; Deutsch, C.; Iwata-Reuyl, D.; Limbach, P. A.; Dedon, P. C.; Rice, K. C.; Shuman, S.; Crécy-Lagard, V. D.
Article Title: The t(6)A modification acts as a positive determinant for the anticodon nuclease PrrC, and is distinctively nonessential in Streptococcus mutans
Abstract: Endoribonuclease toxins (ribotoxins) are produced by bacteria and fungi to respond to stress, eliminate non-self competitor species, or interdict virus infection. PrrC is a bacterial ribotoxin that targets and cleaves tRNALys UUU in the anticodon loop. In vitro studies suggested that the post-transcriptional modification threonylcarbamoyl adenosine (t6A) is required for PrrC activity but this prediction had never been validated in vivo. Here, by using t6A-deficient yeast derivatives, it is shown that t6A is a positive determinant for PrrC proteins from various bacterial species. Streptococcus mutans is one of the few bacteria where the t6A synthesis gene tsaE (brpB) is dispensable and its genome encodes a PrrC toxin. We had previously shown using an HPLC-based assay that the S. mutans tsaE mutant was devoid of t6A. However, we describe here a novel and a more sensitive hybridization-based t6A detection method (compared to HPLC) that showed t6A was still present in the S. mutans ΔtsaE, albeit at greatly reduced levels (93% reduced compared with WT). Moreover, mutants in 2 other S. mutans t6A synthesis genes (tsaB and tsaC) were shown to be totally devoid of the modification thus confirming its dispensability in this organism. Furthermore, analysis of t6A modification ratios and of t6A synthesis genes mRNA levels in S. mutans suggest they may be regulated by growth phase. © 2018, © 2018 Taylor & Francis Group, LLC.
Keywords: translation; modified nucleosides; rna maturation; t6a detection
Journal Title: RNA Biology
Volume: 15
Issue: 4-5
ISSN: 1547-6286
Publisher: Taylor & Francis Group  
Date Published: 2018-05-04
Start Page: 508
End Page: 517
Language: English
DOI: 10.1080/15476286.2017.1353861
PROVIDER: scopus
PMCID: PMC6103680
PUBMED: 28726545
DOI/URL:
Notes: Review -- Export Date: 4 September 2018 -- Source: Scopus
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  1. Stewart H Shuman
    546 Shuman