Conserved Protein Domain Family

cl21406: CdiA-CT_Ec_tRNase Superfamily 
Click on image for an interactive view with Cn3D
C-terminal (CT) domain of the contact-dependent growth inhibition (CDI) system protein CdiA (CdiA-CT) of Escherichia coli 563, and similar proteins
CDI toxins are expressed by gram-negative bacteria as part of a mechanism to inhibit the growth of neighboring cells. 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 the C-terminal domain. A wide variety of C-terminal toxin domains appear to exist; this particular model contains the C-terminal (CT) domain Escherichia coli 563 CdiA and similar domains. This CdiA-CT (EC536) region is composed of two domains that have distinct functions during CDI. This domain is the extreme C-terminal domain, an RNase toxin that possesses an all alpha-helical fold and conserved aspartate and glutamate residues, and K[DE] and [DN]HxxE motifs. The N-terminal domain facilitates translocation of the tethered nuclease into the cytosol of target bacteria. Although this CdiA-CT rapidly cleaves tRNA in vivo, the purified toxin has no detectable nuclease activity in vitro. Experiments show that it is activated when bound to the biosynthetic enzyme O-acetylserine sulfhydrylase-A (CysK), which is one of two isoenzymes (along with CysM) that catalyze the final reaction in cysteine synthesis. CDI(+) bacteria also produce a CDI immunity protein (CdiI) to specifically neutralize the CdiA-CT toxins to prevent auto-inhibition. This CdiA-CT binds its cognate CdiI with high affinity.
Accession: cl21406
PSSM Id: 419639
Name: CdiA-CT_Ec_tRNase
Created: 16-Jan-2014
Updated: 4-Oct-2023
| Disclaimer | Privacy statement | Accessibility |
NCBI Home NCBI Search NCBI SiteMap