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The Intervening Sequence of Coxiella burnetii: Characterization and Evolution.
- Source :
-
Frontiers in cellular and infection microbiology [Front Cell Infect Microbiol] 2016 Aug 19; Vol. 6, pp. 83. Date of Electronic Publication: 2016 Aug 19 (Print Publication: 2016). - Publication Year :
- 2016
-
Abstract
- The intervening sequence (IVS) of Coxiella burnetii, the agent of Q fever, is a 428-nt selfish genetic element located in helix 45 of the precursor 23S rRNA. The IVS element, in turn, contains an ORF that encodes a hypothetical ribosomal S23 protein (S23p). Although S23p can be synthesized in vitro in the presence of an engineered E. coli promoter and ribosome binding site, results suggest that the protein is not synthesized in vivo. In spite of a high degree of IVS conservation among different strains of C. burnetii, the region immediately upstream of the S23p start codon is prone to change, and the S23p-encoding ORF is evidently undergoing reductive evolution. We determined that IVS excision from 23S rRNA was mediated by RNase III, and IVS RNA was rapidly degraded, thereafter. Levels of the resulting 23S rRNA fragments that flank the IVS, F1 (~1.2 kb) and F2 (~1.7 kb), were quantified over C. burnetii's logarithmic growth phase (1-5 d). Results showed that 23S F1 quantities were consistently higher than those of F2 and 16S rRNA. The disparity between levels of the two 23S rRNA fragments following excision of IVS is an interesting phenomenon of unknown significance. Based upon phylogenetic analyses, IVS was acquired through horizontal transfer after C. burnetii's divergence from an ancestral bacterium and has been subsequently maintained by vertical transfer. The widespread occurrence, maintenance and conservation of the IVS in C. burnetii imply that it plays an adaptive role or has a neutral effect on fitness.
- Subjects :
- Amino Acid Sequence
Base Sequence
Coxiella burnetii growth & development
Coxiella burnetii metabolism
DNA, Bacterial genetics
DNA, Ribosomal genetics
Escherichia coli genetics
Evolution, Molecular
Gene Transfer, Horizontal
Genes, Bacterial
Nucleic Acid Conformation
Phylogeny
Protein Structure, Secondary
Q Fever microbiology
RNA Splicing
RNA, Bacterial genetics
RNA, Ribosomal, 16S genetics
Ribonuclease III genetics
Coxiella burnetii genetics
Introns
RNA, Ribosomal, 23S genetics
Subjects
Details
- Language :
- English
- ISSN :
- 2235-2988
- Volume :
- 6
- Database :
- MEDLINE
- Journal :
- Frontiers in cellular and infection microbiology
- Publication Type :
- Academic Journal
- Accession number :
- 27595093
- Full Text :
- https://doi.org/10.3389/fcimb.2016.00083