A genomic island present along the bacterial chromosome of the Parachlamydiaceae UWE25, an obligate amoebal endosymbiont, encodes a potentially functional F-like conjugative DNA transfer system
العنوان: | A genomic island present along the bacterial chromosome of the Parachlamydiaceae UWE25, an obligate amoebal endosymbiont, encodes a potentially functional F-like conjugative DNA transfer system |
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المؤلفون: | Greub, Gilbert, Collyn, François, Guy, Lionel, Roten, Claude-Alain |
المساهمون: | Center for Research on Intracellular Bacteria, Université de Lausanne = University of Lausanne (UNIL)-Institute of Microbiology, Interactions cellulaires et moléculaires des bactéries pathogènes avec l'hôte, Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Biologie-Université de Lille, Droit et Santé, Department of Fundamental Microbiology [Lausanne], Université de Lausanne = University of Lausanne (UNIL), Maylin, Françoise |
المصدر: | BMC Microbiology, vol. 4, no. 1, pp. 48 BMC Microbiology BMC Microbiology, Vol 4, Iss 1, p 48 (2004) BMC Microbiology, BioMed Central, 2004, 4, pp.48. ⟨10.1186/1471-2180-4-48⟩ |
سنة النشر: | 2004 |
مصطلحات موضوعية: | DNA, Bacterial, MESH: Operon, MESH: Chromosomes, Bacterial, MESH: Chlamydiales, Genomic Islands, lcsh:QR1-502, Acanthamoeba, lcsh:Microbiology, MESH: Gene Order, MESH: Base Composition, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Gene Order, Operon, MESH: Acanthamoeba, MESH: Genomic Islands, Animals, MESH: Animals, MESH: Phylogeny, Symbiosis, [SDV.MP] Life Sciences [q-bio]/Microbiology and Parasitology, Phylogeny, Base Composition, MESH: Symbiosis, Chlamydiales, Computational Biology, MESH: Conjugation, Genetic, Chromosomes, Bacterial, MESH: DNA, Bacterial, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, Conjugation, Genetic, [SDV.BBM.GTP] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], MESH: Computational Biology, Research Article, Acanthamoeba/microbiology, Base Composition/genetics, Chlamydiales/classification, Chlamydiales/genetics, Chromosomes, Bacterial/genetics, Computational Biology/methods, Conjugation, Genetic/genetics, DNA, Bacterial/genetics, Gene Order/genetics, Genomic Islands/genetics, Operon/genetics |
الوصف: | Background The genome of Protochlamydia amoebophila UWE25, a Parachlamydia-related endosymbiont of free-living amoebae, was recently published, providing the opportunity to search for genomic islands (GIs). Results On the residual cumulative G+C content curve, a G+C-rich 19-kb region was observed. This sequence is part of a 100-kb chromosome region, containing 100 highly co-oriented ORFs, flanked by two 17-bp direct repeats. Two identical gly-tRNA genes in tandem are present at the proximal end of this genetic element. Several mobility genes encoding transposases and bacteriophage-related proteins are located within this chromosome region. Thus, this region largely fulfills the criteria of GIs. The G+C content analysis shows that several modules compose this GI. Surprisingly, one of them encodes all genes essential for F-like conjugative DNA transfer (traF, traG, traH, traN, traU, traW, and trbC), involved in sex pilus retraction and mating pair stabilization, strongly suggesting that, similarly to the other F-like operons, the parachlamydial tra unit is devoted to DNA transfer. A close relatedness of this tra unit to F-like tra operons involved in conjugative transfer is confirmed by phylogenetic analyses performed on concatenated genes and gene order conservation. These analyses and that of gly-tRNA distribution in 140 GIs suggest a proteobacterial origin of the parachlamydial tra unit. Conclusions A GI of the UWE25 chromosome encodes a potentially functional F-like DNA conjugative system. This is the first hint of a putative conjugative system in chlamydiae. Conjugation most probably occurs within free-living amoebae, that may contain hundreds of Parachlamydia bacteria tightly packed in vacuoles. Such a conjugative system might be involved in DNA transfer between internalized bacteria. Since this system is absent from the sequenced genomes of Chlamydiaceae, we hypothesize that it was acquired after the divergence between Parachlamydiaceae and Chlamydiaceae, when the Parachlamydia-related symbiont was an intracellular bacteria. It suggests that this heterologous DNA was acquired from a phylogenetically-distant bacteria sharing an amoebal vacuole. Since Parachlamydiaceae are emerging agents of pneumonia, this GI might be involved in pathogenicity. In future, conjugative systems might be developed as genetic tools for Chlamydiales. |
وصف الملف: | application/pdf |
اللغة: | English |
تدمد: | 1471-2180 |
URL الوصول: | https://explore.openaire.eu/search/publication?articleId=pmid_dedup__::92723234816e2497f78bb9d4c0efbbe7 https://serval.unil.ch/resource/serval:BIB_D9A310F15FF8.P001/REF.pdf |
حقوق: | OPEN |
رقم الأكسشن: | edsair.pmid.dedup....92723234816e2497f78bb9d4c0efbbe7 |
قاعدة البيانات: | OpenAIRE |
تدمد: | 14712180 |
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