Identification of functional toxin/immunity genes linked to contact-dependent growth inhibition (CDI) and rearrangement hotspot (Rhs) systems.

ABSTRACT: Bacterial contact-dependent growth inhibition (CDI) is mediated by the CdiA/CdiB family of two-partner secretion proteins. Each CdiA protein exhibits a distinct growth inhibition activity, which resides in the polymorphic C-terminal region (CdiA-CT). CDI(+) cells also express unique CdiI immunity proteins that specifically block the activity of cognate CdiA-CT, thereby protecting the cell from autoinhibition. Here we show that many CDI systems contain multiple cdiA gene fragments that encode CdiA-CT sequences. These "orphan" cdiA-CT genes are almost always associated with downstream cdiI genes to form cdiA-CT/cdiI modules. Comparative genome analyses suggest that cdiA-CT/cdiI modules are mobile and exchanged between the CDI systems of different bacteria. In many instances, orphan cdiA-CT/c

SUBMITTER: Poole SJ 

PROVIDER: S-EPMC3150448 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature