3 Ontology Annotations
| GO Term | Gene Name |
|---|---|
| GO:0005509 | IPR003995 |
| GO:0009405 | IPR003995 |
| GO:0005576 | IPR003995 |
| Type: | Family | Name: | RTX toxin determinant A |
| Description: | Secretion of virulence factors in Gram-negative bacteria involves transportation of the protein across two membranes to reach the cell exterior []. Four principal exotoxin secretion systems have been described. In the type II and IV secretion systems, toxins are first exported to the periplasm by way of a cleaved N-terminal signal sequence; a second set of proteins is used for extracellular transport (type II), or the C terminus of the exotoxin itself is used (type IV). Type III secretion involves at least 20 molecules that assemble into a needle; effector proteins are then translocated through this without need of a signal sequence. In the Type I system, a complete channel is formed through both membranes, and the secretion signal is carried on the C terminus of the exotoxin. The RTX (repeats in toxin) family of cytolytic toxins belong to the Type I secretion system, and are important virulence factors in Gram-negative bacteria. As well as the C-terminal signal sequence, several glycine-richrepeats are also found. These are essential for binding calcium, and are critical for the biological activity of the secreted toxins []. All RTX toxin operons exist in the order rtxCABD, RtxA protein being the structuralcomponent of the exotoxin, both RtxB and D being required for its export from the bacterial cell; RtxC is an acyl-carrier-protein-dependent acyl- modification enzyme, required to convert RtxA to its active form [].Escherichia colihaemolysin (HlyA) is often quoted as the model for RTX toxins. Recent work on its relative rtxC gene product HlyC [] has revealed that it provides the acylation aspect for post-translational modification of two internal lysine residues in the HlyA protein. To cause pathogenicity, the HlyA toxin must first bind Ca2+ ions to the set of glycine-rich repeats and then be activated by HlyC []. This has been demonstrated both in vitroand in vivo. | Short Name: | RTX_toxin_determinant-A |
| GO Term | Gene Name |
|---|---|
| GO:0005509 | IPR003995 |
| GO:0009405 | IPR003995 |
| GO:0005576 | IPR003995 |
