Published In

Journal of Bacteriology

Document Type


Publication Date



Genomics, Non-coding RNA, Bacterial genomes


Coxiella burnetii is an obligate intracellular gammaproteobacterium and zoonotic agent of Q fever. We previously identified 15 small non-coding RNAs (sRNAs) of C. burnetii. One of them, CbsR12 (Coxiella b urnetii small RNA 12), is highly transcribed during axenic growth and becomes more prominent during infection of cultured mammalian cells. Secondary structure predictions of CbsR12 revealed four putative CsrA-binding sites in stem loops with consensus AGGA/ANGGA motifs. We subsequently determined that CbsR12 binds to recombinant C. burnetii CsrA-2, but not CsrA-1, proteins in vitro. Moreover, through a combination of in vitro and cell culture assays, we identified several in-trans mRNA targets of CbsR12. Of these, we determined that CbsR12 binds and upregulates translation of carA transcripts coding for carbamoyl phosphate synthetase A; an enzyme that catalyzes the first step of pyrimidine biosynthesis. In addition, CbsR12 binds and downregulates translation of metK transcripts coding for S-adenosyl methionine (SAM) synthetase, a component of the methionine cycle. Furthermore, we found that CbsR12 binds to and downregulates the quantity of cvpD transcripts, coding for a type IVB effector protein, in mammalian cell culture. Finally, we found that CbsR12 is necessary for expansion of Coxiella-containing vacuoles (CCVs) and affects growth rates in a dose-dependent manner in the early phase of infecting THP-1 cells. This is the first characterization of a trans-acting sRNA of C. burnetii and first example of a bacterial sRNA that regulates both CarA and MetK synthesis. CbsR12 is one of only a few identified trans-acting sRNAs that interacts with CsrA.


This is the author’s version of a work that was accepted for publication in Journal of Bacteriology,. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Bacteriology (2019), and can be found here:

Copyright © 2019 American Society for Microbiology



Persistent Identifier

Included in

Biology Commons