RTX (Repeat in ToXin) superfamily consists of many proteins divided into several groups according to their different functions and characteristics: toxins, metalloproteases, lipases, proteins of the S-layer, bacteriocins and proteins with unknown function. However, all of them can be characterized by the following features: i) they contain tandemly repeated (6-50) nonapeptide glycine-rich calcium-binding consensus sequences GGXGXDX[L/I/V/W/Y/F]X (where X is any amino acid residue) in the C-terminal part of the protein. The presence of these repeats is a sine qua non condition for RTX protein family membership; ii) secretion from the cell occurs without a periplasmic intermediate by a mechanism which involves recognition of a signal sequence at the C-terminus of the protein by membrane-associated proteins that export the toxin across a channel spanning the entire bacterial envelope directly to the outside of the cell (Type I Secretion System); iii) the genes for protein synthesis, activation and secretion are mostly grouped together on the chromosome and form rtx operons. RTX toxins are the largest protein group of the RTX family. To this group belong mostly the proteins with molecular weight ranging from 100 to 200 kDa, with posttranslational fatty acid acylation mediated by a specific activating...
Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:329285 |
Date | January 2013 |
Creators | Sadílková, Lenka |
Contributors | Šebo, Peter, Stulík, Jiří, Weiser, Jaroslav |
Source Sets | Czech ETDs |
Language | Czech |
Detected Language | English |
Type | info:eu-repo/semantics/doctoralThesis |
Rights | info:eu-repo/semantics/restrictedAccess |
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