4DMW

Crystal structure of the GT domain of Clostridium difficile toxin A (TcdA) in complex with UDP and Manganese

4DMW の概要

• エントリーDOI: 10.2210/pdb4dmw/pdb
• 関連するPDBエントリー: 3SRZ 3SS1 4DMV
• 分子名称: Toxin A, MANGANESE (II) ION, URIDINE-5'-DIPHOSPHATE, ... (4 entities in total)
• 機能のキーワード: glucosyltransferase, transferase
• 由来する生物種: Clostridium difficile
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 65000.77

構造登録者

Malito, E.,D'Urzo, N.,Bottomley, M.J.,Biancucci, M.,Scarselli, M.,Maione, D.,Martinelli, M. (登録日: 2012-02-08, 公開日: 2012-07-18, 最終更新日: 2023-09-13)

主引用文献

D'Urzo, N.,Malito, E.,Biancucci, M.,Bottomley, M.J.,Maione, D.,Scarselli, M.,Martinelli, M.
The structure of Clostridium difficile toxin A glucosyltransferase domain bound to Mn2+ and UDP provides insights into glucosyltransferase activity and product release.
Febs J., 279:3085-3097, 2012

PubMed Abstract: Clostridiumdifficile toxin A (TcdA) is a member of the large clostridial toxin family, and is responsible, together with C. difficile toxin B (TcdB), for many clinical symptoms d ring human infections. Like other large clostridial toxins, TcdA catalyzes the glucosylation of GTPases, and is able to inactivate small GTPases within the host cell. Here, we report the crystal structures of the TcdA glucosyltransferase domain (TcdA-GT) in the apo form and in the presence of Mn(2+) and hydrolyzed UDP-glucose. These structures, together with the recently reported crystal structure of TcdA-GT bound to UDP-glucose, provide a detailed understanding of the conformational changes of TcdA that occur during the catalytic cycle. Indeed, we present a new intermediate conformation of a so-called 'lid' loop (residues 510-522 in TcdA), concomitant with the absence of glucose in the catalytic domain. The recombinant TcdA was expressed in Brevibacillus in the inactive apo form. High thermal stability of wild-type TcdA was observed only after the addition of both Mn(2+) and UDP-glucose. The glucosylhydrolase activity, which is readily restored after reconstitution with both these cofactors, was similar to that reported for TcdB. Interestingly, we found that ammonium, like K(+) , is able to activate the UDP-glucose hydrolase activities of TcdA. Consequently, the presence of ammonium in the crystallization buffer enabled us to obtain the first crystal structure of TcdA-GT bound to the hydrolysis product UDP.

PubMed: 22747490
DOI: 10.1111/j.1742-4658.2012.08688.x

実験手法

X-RAY DIFFRACTION (2.5 Å)