Conserved Protein Domain Family

cl39583: CdiI_ECL-like Superfamily 
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inhibitor (or immunity protein) of the contact-dependent growth inhibition (CDI) system of Enterobacter cloacae, and similar proteins
CDI toxins are expressed by gram-negative bacteria as part of a mechanism to inhibit the growth of neighboring cells. This model represents the inhibitor (CdiI, also called CdiI immunity protein) of the CdiA effector protein from Enterobacter cloacae, and similar proteins. CdiA secretion is dependent on the outer membrane protein CdiB. Upon binding to a receptor on the surface of target bacteria, the CDI toxin is delivered via its C-terminal domain (CdiA-CT). The CdiI immunity proteins are intracellular proteins that inactivate the toxin/effector protein to prevent auto-inhibition. They are specific for their cognate CdiA-CT and do not protect cells from the toxins of other CDI+ bacteria. Thus, CDI systems encode a complex network of toxin-immunity protein pairs that are deployed for intercellular competition. Although E. cloacae CdiA-CT has structural homology to the C-terminal nuclease domain of colicin E3, which cleaves 16S ribosomal RNA to disrupt protein synthesis, and has been shown to use the same nuclease activity to inhibit bacterial growth, the corresponding CdiI immunity proteins are unrelated in sequence, structure and toxin-binding sites. Structural homology searches reveal that E. cloacae CdiI is most similar to the Whirly family of single-stranded DNA-binding proteins.
Accession: cl39583
PSSM Id: 423385
Name: CdiI_ECL-like
Created: 8-Jan-2020
Updated: 24-Nov-2020
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