Structural basis of toxicity and immunity in contact-dependent growth inhibition (CDI) systems
- 10 December 2012
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 109 (52), 21480-21485
- https://doi.org/10.1073/pnas.1216238110
Abstract
Contact-dependent growth inhibition (CDI) systems encode polymorphic toxin/immunity proteins that mediate competition between neighboring bacterial cells. We present crystal structures of CDI toxin/immunity complexes from Escherichia coli EC869 and Burkholderia pseudomallei 1026b. Despite sharing little sequence identity, the toxin domains are structurally similar and have homology to endonucleases. The EC869 toxin is a Zn(2+)-dependent DNase capable of completely degrading the genomes of target cells, whereas the Bp1026b toxin cleaves the aminoacyl acceptor stems of tRNA molecules. Each immunity protein binds and inactivates its cognate toxin in a unique manner. The EC869 toxin/immunity complex is stabilized through an unusual β-augmentation interaction. In contrast, the Bp1026b immunity protein exploits shape and charge complementarity to occlude the toxin active site. These structures represent the initial glimpse into the CDI toxin/immunity network, illustrating how sequence-diverse toxins adopt convergent folds yet retain distinct binding interactions with cognate immunity proteins. Moreover, we present visual demonstration of CDI toxin delivery into a target cell.Keywords
This publication has 31 references indexed in Scilit:
- The toxin/immunity network of Burkholderia pseudomallei contact‐dependent growth inhibition (CDI) systemsMolecular Microbiology, 2012
- Identification of a target cell permissive factor required for contact-dependent growth inhibition (CDI)Genes & Development, 2012
- A novel immunity system for bacterial nucleic acid degrading toxins and its recruitment in various eukaryotic and DNA viral systemsNucleic Acids Research, 2011
- A widespread family of polymorphic contact-dependent toxin delivery systems in bacteriaNature, 2010
- Crystal structure of the ββα-Me type II restriction endonuclease Hpy99I with target DNANucleic Acids Research, 2009
- Contact-Dependent Growth Inhibition Causes Reversible Metabolic Downregulation in Escherichia coliJournal of Bacteriology, 2009
- Protein acrobatics in pairs — dimerization via domain swappingCurrent Opinion in Structural Biology, 2009
- Contact‐dependent growth inhibition requires the essential outer membrane protein BamA (YaeT) as the receptor and the inner membrane transport protein AcrBMolecular Microbiology, 2008
- Searching protein structure databases with DaliLite v.3Bioinformatics, 2008
- Competitive recruitment of the periplasmic translocation portal TolB by a natively disordered domain of colicin E9Proceedings of the National Academy of Sciences of the United States of America, 2006