Dataset Information

Contact-dependent growth inhibition systems in Acinetobacter.

ABSTRACT: In bacterial contact-dependent growth inhibition (CDI) systems, CdiA proteins are exported to the outer membrane by cognate CdiB proteins. CdiA binds to receptors on susceptible bacteria and subsequently delivers its C-terminal toxin domain (CdiA-CT) into neighbouring target cells. Whereas self bacteria produce CdiI antitoxins, non-self bacteria lack antitoxins and are therefore inhibited in their growth by CdiA. In silico surveys of pathogenic Acinetobacter genomes have enabled us to identify >40 different CDI systems, which we sorted into two distinct groups. Type-II CdiAs are giant proteins (3711 to 5733 residues) with long arrays of 20-mer repeats. Type-I CdiAs are smaller (1900-2400 residues), lack repeats and feature central heterogeneity (HET) regions, that vary in size and sequence and can be exchanged between CdiA proteins. HET regions in most type-I proteins confer the ability to adopt a coiled-coil conformation. CdiA-CT and pretoxin modules differ significantly between type-I and type-II CdiAs. Moreover, type-II genes only have remnants of genes in their 3' end regions that have been displaced by the insertion of novel cdi sequences. Type-I and type-II CDI systems are equally abundant in A. baumannii, whereas A. pittii and A. nosocomialis predominantly feature type-I and type-II systems, respectively.

SUBMITTER: De Gregorio E

PROVIDER: S-EPMC6336857 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Contact-dependent growth inhibition systems in Acinetobacter.

De Gregorio Eliana E Zarrilli Raffaele R Di Nocera Pier Paolo PP

Scientific reports 20190117 1

In bacterial contact-dependent growth inhibition (CDI) systems, CdiA proteins are exported to the outer membrane by cognate CdiB proteins. CdiA binds to receptors on susceptible bacteria and subsequently delivers its C-terminal toxin domain (CdiA-CT) into neighbouring target cells. Whereas self bacteria produce CdiI antitoxins, non-self bacteria lack antitoxins and are therefore inhibited in their growth by CdiA. In silico surveys of pathogenic Acinetobacter genomes have enabled us to identify > ...[more]

PMID: 30655547

Similar Datasets

Project description:Burkholderia species, including opportunistic pathogens in the Burkholderia cepacia complex (Bcc), have genes to produce contact-dependent growth inhibition (CDI) system proteins. CDI is a phenomenon in which Gram-negative bacteria use the toxic C terminus of a polymorphic surface-exposed exoprotein, BcpA, to inhibit the growth of susceptible bacteria upon direct cell-cell contact. Production of a small immunity protein, BcpI, prevents autoinhibition. Although CDI systems appear widespread in Gram-negative bacteria, their function has been primarily examined in several model species. Here we demonstrate that genes encoding predicted CDI systems in Bcc species exhibit considerable diversity. We also show that Burkholderia multivorans, which causes pulmonary infections in patients with cystic fibrosis, expresses genes that encode two CDI systems, both of which appear distinct from the typical Burkholderia-type CDI system. Each system can mediate intrastrain interbacterial competition and contributes to bacterial adherence. Surprisingly, the immunity-protein-encoding bcpI gene of CDI system 1 could be mutated without obvious deleterious effects. We also show that nonpathogenic Burkholderia thailandensis uses CDI to control B. multivorans growth during coculture, providing one of the first examples of interspecies CDI and suggesting that CDI systems could be manipulated to develop therapeutic strategies targeting Bcc pathogens.IMPORTANCE Competition among bacteria affects microbial colonization of environmental niches and host organisms, particularly during polymicrobial infections. The Bcc is a group of environmental bacteria that can cause life-threatening opportunistic infections in patients who have cystic fibrosis or are immunocompromised. Understanding the mechanisms used by these bacterial pathogens to compete with one another may lead to the development of more effective therapies. Findings presented here demonstrate that a Bcc species, Burkholderia multivorans, produces functional CDI system proteins and that growth of this pathogen can be controlled by CDI system proteins produced by neighboring Burkholderia cells.

Dataset Information

Contact-dependent growth inhibition systems in Acinetobacter.

Publications

Contact-dependent growth inhibition systems in Acinetobacter.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure