Evidence for a modular structure of the homologous repetitive C-terminal carbohydrate-binding sites of Clostridium difficile toxins and Streptococcus mutans glucosyltransferases.
The homologous C-terminal repeats of Clostridium difficile toxins (ToxA and ToxB) and streptococcal glucosyltransferases appear to mediate protein-carbohydrate interactions at cellular binding sites with sugar moieties as substrates. A consensus sequence of 134 repeating units from gram-positive bacteria indicates that these repeats have a modular design with (i) a stretch of aromatic amino acids proposed to be involved in the primary carbohydrate-protein interaction, (ii) an amplification of this interaction by repetition of the respective sequences, and (iii) a second domain, not characterized, that is responsible for carbohydrate specificity.
von Eichel-Streiber
C
C
Institut für Medizinische Mikrobiologie, Johannes-Gutenberg-Universität, Mainz, Federal Republic of Germany.
Sauerborn
M
M
Kuramitsu
H K
HK
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D001427:Bacterial Toxins / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D050260:Carbohydrate Metabolism; D016360:Clostridioides difficile / Q000737:chemistry*; D016384:Consensus Sequence; D003603:Cytotoxins / Q000737:chemistry*; D004768:Enterotoxins / Q000737:chemistry* / Q000378:metabolism; D005964:Glucosyltransferases / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D013295:Streptococcus mutans / Q000201:enzymology*
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D003603:Cytotoxins; D004768:Enterotoxins; C041348:tcdA protein, Clostridium difficile; C031815:toxB protein, Clostridium difficile; D005964:Glucosyltransferases