Bioinformatic Analysis of the Campylobacter jejuni Type VI Secretion System and Effector Prediction
Date
2021-06-29
Journal Title
Journal ISSN
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Publisher
Frontiers Media
Abstract
The Type VI Secretion System (T6SS) has important roles relating to bacterial
antagonism, subversion of host cells, and niche colonisation. Campylobacter jejuni
is one of the leading bacterial causes of human gastroenteritis worldwide and is
a commensal coloniser of birds. Although recently discovered, the T6SS biological
functions and identities of its effectors are still poorly defined in C. jejuni. Here, we
perform a comprehensive bioinformatic analysis of the C. jejuni T6SS by investigating the
prevalence and genetic architecture of the T6SS in 513 publicly available genomes using
C. jejuni 488 strain as reference. A unique and conserved T6SS cluster associated with
the Campylobacter jejuni Integrated Element 3 (CJIE3) was identified in the genomes of
117 strains. Analyses of the T6SS-positive 488 strain against the T6SS-negative C. jejuni
RM1221 strain and the T6SS-positive plasmid pCJDM202 carried by C. jejuni WP2-202
strain defined the “T6SS-containing CJIE3” as a pathogenicity island, thus renamed
as Campylobacter jejuni Pathogenicity Island-1 (CJPI-1). Analysis of CJPI-1 revealed
two canonical VgrG homologues, CJ488_0978 and CJ488_0998, harbouring distinct
C-termini in a genetically variable region downstream of the T6SS operon. CJPI-1 was
also found to carry a putative DinJ-YafQ Type II toxin-antitoxin (TA) module, conserved
across pCJDM202 and the genomic island CJIE3, as well as several open reading
frames functionally predicted to encode for nucleases, lipases, and peptidoglycan
hydrolases. This comprehensive in silico study provides a framework for experimental
characterisation of T6SS-related effectors and TA modules in C. jejuni
Description
Publication history: Accepted - 7 June 2021; Published online - 29 June 2021.
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Keywords
Campylobacter jejuni, Type VI Secretion System, T6SS effectors, T6SS immunity proteins, toxin-antitoxin, pathogenicity island
Citation
Robinson, L., Liaw, J., Omole, Z., Xia, D., van Vliet, A. H. M., Corcionivoschi, N., Hachani, A. and Gundogdu, O. (2021) ‘Bioinformatic Analysis of the Campylobacter jejuni Type VI Secretion System and Effector Prediction’, Frontiers in Microbiology, 12. doi: 10.3389/fmicb.2021.694824.