Skip to Main content Skip to Navigation
Journal articles

Mycobacterial pan-genome analysis suggests important role of plasmids in the radiation of type VII secretion systems

Abstract : In mycobacteria, various type VII secretion systems corresponding to different ESX (ESAT-6 secretory) types, are contributing to pathogenicity, iron acquisition, and/or conjugation. In addition to the known chromosomal ESX loci, the existence of plasmid-encoded ESX systems was recently reported. To investigate the potential role of ESX-encoding plasmids on mycobacterial evolution we analysed a large representative collection of mycobacterial genomes, including both chromosomal and plasmid-borne sequences. Data obtained for chromosomal ESX loci confirmed the previous 5 classical ESX types and identified a novel mycobacterial ESX-4-like type, termed ESX-4-bis. Moreover, analysis of the plasmid-encoded ESX loci showed extensive diversification, with at least 7 new ESX profiles, identified. Three of them (ESX-P clusters 1, 2 and 3) were found in multiple plasmids, while four corresponded to singletons. Our phylogenetic and gene-order-analyses revealed two main groups of ESX types: i) ancestral types, including ESX-4 and ESX-4-like systems from mycobacterial and non-mycobacterial actinobacteria, and ii) mycobacteria-specific ESX systems, including ESX-1-2-3-5 systems and the plasmid-encoded ESX types. Synteny analysis revealed that ESX-P systems are part of phylogenetic groups that derived from a common ancestor, which diversified and resulted in the different ESX types through extensive gene rearrangements. A converging body of evidence, derived from composition bias-, phylogenetic- and synteny analyses points to a scenario in which ESX-encoding plasmids have been a major driving force for acquisition and diversification of type VII systems in mycobacteria, which likely played (and possibly still play) important roles in the adaptation to new environments and hosts during evolution of mycobacterial pathogenesis.
Document type :
Journal articles
Complete list of metadata

Cited literature [69 references]  Display  Hide  Download
Contributor : Gestionnaire Hal-Upmc Connect in order to contact the contributor
Submitted on : Monday, March 21, 2016 - 3:57:27 PM
Last modification on : Thursday, November 25, 2021 - 11:42:02 AM
Long-term archiving on: : Sunday, November 13, 2016 - 9:50:17 PM


Genome Biol Evol-2016-Dumas-gb...
Publication funded by an institution


Distributed under a Creative Commons Attribution 4.0 International License



Emilie Dumas, Eva Christina Boritsch, Mathias Vandenbogaert, Ricardo C. Rodriguez de la Vega, Jean-Michel Thiberge, et al.. Mycobacterial pan-genome analysis suggests important role of plasmids in the radiation of type VII secretion systems. Genome Biology and Evolution, Society for Molecular Biology and Evolution, 2016, 8 (2), pp.387-402. ⟨10.1093/gbe/evw001⟩. ⟨hal-01291528⟩



Record views


Files downloads