The name of this superfamily has been modified since the most recent official CATH+ release (v4_4_0). At the point of the last release, this superfamily was named:
"Novel toxin 21 (CdiA), C-terminal domain
".
3.10.380.20
superfamily
Bacterial genomes and plasmids encode a variety of peptide and protein toxins that mediate inter-bacterial competition. Bacteriocins are diffusible proteins that parasitize cell-envelope proteins to enter and kill bacteria. Contact-dependent growth inhibition (CDI) is one mechanism of inter-bacterial competition. Novel Toxin 21 (alternatively 16S rRNA endonuclease CdiA) belongs to a family of prokaryotic polymorphic toxin systems implicated in intra-specific conflicts PMID:24657090. This RNase toxin found in bacterial polymorphic toxin systems, is proposed to adopt the BECR (Barnase-EndoU-ColicinE5/D-RelE) fold, with two conserved lysine residues and [DS]xDxxxH, RxG[ST] and RxxD motifs. In bacterial polymorphic toxin systems, the toxin is usually exported by the type 2, type 4, type 5 or type 7 secretion systems PMID:22731697. This is also referred to as the E. cloacae CdiAC PMID:24657090. The CdiAC proteins carry a variety of sequence-diverse C-terminal domains, which represent a collection of distinct toxins PMID:22731697. Many CdiA-CT toxins have nuclease activities. In accord with the structural homology, CdiA-CT cleaves 16S rRNA at the same site as colicin E3 and this nuclease activity is responsible for growth inhibition PMID:24657090. These toxins are composed of three domains, each responsible for a distinct step in the cell-killing pathway. The central domain binds specific receptors on the surface of susceptible bacteria, the N-terminal domain mediates translocation across the cell envelope, and the C-terminal domain carries the bacteriocidal activity. This modular structure allows for delivery of diverse C-terminal toxins using conserved translocation and receptor-binding domains PMID:24657090.
PFAM:PF15526, INTERPRO:IPR028190,DOI:10.1016/j.str.2014.02.012
Structures | |
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Domains: | 1 |
Domain clusters (>95% seq id): | 1 |
Domain clusters (>35% seq id): | 1 |
Unique PDBs: | 1 |
Alignments | |
Structural Clusters (5A): | 1 |
Structural Clusters (9A): | 1 |
FunFam Clusters: | 1 |
Function | |
Unique EC: | |
Unique GO: | 1 |
Taxonomy | |
Unique Species: | 146 |