2BVL

Crystal structure of the catalytic domain of toxin B from Clostridium difficile in complex with UDP, Glc and manganese ion

Summary for 2BVL

• Entry DOI: 10.2210/pdb2bvl/pdb
• Related: 2BVM
• Descriptor: TOXIN B, MANGANESE (II) ION, URIDINE-5'-DIPHOSPHATE, ... (7 entities in total)
• Functional Keywords: toxin, glycosyltransferase
• Biological source: CLOSTRIDIUM DIFFICILE
• Total number of polymer chains: 1
• Total formula weight: 71950.99

Authors

Reinert, D.J.,Jank, T.,Aktories, K.,Schulz, G.E. (deposition date: 2005-06-30, release date: 2005-08-03, Last modification date: 2024-05-08)

Primary citation

Reinert, D.J.,Jank, T.,Aktories, K.,Schulz, G.E.
Structural Basis for the Function of Clostridium Difficile Toxin B.
J.Mol.Biol., 351:973-, 2005

PubMed Abstract: Toxin B is a member of the family of large clostridial cytotoxins which are of great medical importance. Its catalytic fragment was crystallized in the presence of UDP-glucose and Mn2+. The structure was determined at 2.2 A resolution, showing that toxin B belongs to the glycosyltransferase type A family. However, toxin B contains as many as 309 residues in addition to the common chainfold, which most likely contribute to the target specificity. A superposition with other glycosyltransferases shows the expected positions of the acceptor oxygen atom during glucosyl transfer and indicates further that the reaction proceeds probably along a single-displacement pathway. The C1'' donor carbon atom position is defined by the bound UDP and glucose. It assigns the surface area of toxin B that forms the interface to the target protein during the modifying reaction. A docking attempt brought the known acceptor atom, Thr37 O(gamma1) of the switch I region of the RhoA:GDP target structure, near the expected position. The relative orientation of the two proteins was consistent with both being attached to a membrane. Sequence comparisons between toxin B variants revealed that the highest exchange rate occurs around the active center at the putative docking interface, presumably due to a continuous hit-and-evasion struggle between Clostridia and their eukaryotic hosts.

PubMed: 16054646
DOI: 10.1016/J.JMB.2005.06.071

Experimental method

X-RAY DIFFRACTION (2.2 Å)