Contact-Dependent Growth Inhibition (CDI) and CdiB/CdiA Two-Partner Secretion Proteins. Issue 23 (20th November 2015)

• Record Type: Journal Article
• Authors: Willett, Julia L.E.; Ruhe, Zachary C.; Goulding, Celia W.; Low, David A.; Hayes, Christopher S.
• Is Part Of: Journal of molecular biology. Volume 427:Issue 23(2015:Dec. 01)
• Page Start: 3754
• Page End: 3765
• Publication Date: 2015-11-20
• Subjects: CDI contact-dependent growth inhibition -- TPS two-partner secretion -- pmf proton motive force -- ORF open reading frame; biofilms -- self/non-self recognition -- toxin/immunity proteins -- type V secretion; Molecular biology -- Periodicals; Biology -- Periodicals; Biochemistry -- Periodicals; Bacteriology -- Periodicals; Molecular Biology -- Periodicals; Biochemistry -- Periodicals; Biologie moléculaire -- Périodiques; Biologie -- Périodiques; Biochimie -- Périodiques; Moleculaire biologie; Biochemistry; Biology; Molecular biology; Periodicals; 572.805
• DOI: 10.1016/j.jmb.2015.09.010
• Languages: English
• ISSNs: 0022-2836

Abstract

Abstract: Bacteria have developed several strategies to communicate and compete with one another in complex environments. One important mechanism of inter-bacterial competition is contact-dependent growth inhibition (CDI), in which Gram-negative bacteria use CdiB/CdiA two-partner secretion proteins to suppress the growth of neighboring target cells. CdiB is an Omp85 outer-membrane protein that exports and assembles CdiA exoproteins onto the inhibitor cell surface. CdiA binds to receptors on susceptible bacteria and subsequently delivers its C-terminal toxin domain (CdiA-CT) into the target cell. CDI systems also encode CdiI immunity proteins, which specifically bind to the CdiA-CT and neutralize its toxin activity, thereby protecting CDI + cells from auto-inhibition. Remarkably, CdiA-CT sequences are highly variable between bacteria, as are the corresponding CdiI immunity proteins. Variations in CDI toxin/immunity proteins suggest that these systems function in bacterial self/non-self recognition and thereby play an important role in microbial communities. In this review, we discuss recent advances in the biochemistry, structural biology and physiology of CDI. Graphical Abstract: Highlights: Contact-dependent growth inhibition (CDI) systems mediate inter-bacterial competition. CdiA effector proteins carry a variety of C-terminal toxin domains. CDI toxins are specifically neutralized by cognate immunity proteins. CDI systems also contribute to community structure by promoting biofilm formation.