7LOU

Crystal structure of Clostridium difficile Toxin B (TcdB) glucosyltransferase in complex with UDP and isofagomine

Summary for 7LOU

• Entry DOI: 10.2210/pdb7lou/pdb
• Descriptor: Glucosyltransferase TcdB, 1,2-ETHANEDIOL, URIDINE-5'-DIPHOSPHATE, ... (6 entities in total)
• Functional Keywords: inhibitors, tcdb, toxin, kinetic isotope effects, kies, drug design, transferase, transferase-inhibitor complex, transferase/inhibitor
• Biological source: Clostridioides difficile (Peptoclostridium difficile)
• Total number of polymer chains: 2
• Total formula weight: 131019.51

Authors

Harijan, R.K.,Paparella, A.S.,Aboulache, B.L.,Bonanno, J.B.,Almo, S.C.,Schramm, V.L. (deposition date: 2021-02-10, release date: 2021-11-17, Last modification date: 2023-10-18)

Primary citation

Paparella, A.S.,Aboulache, B.L.,Harijan, R.K.,Potts, K.S.,Tyler, P.C.,Schramm, V.L.
Inhibition of Clostridium difficile TcdA and TcdB toxins with transition state analogues.
Nat Commun, 12:6285-6285, 2021

PubMed Abstract: Clostridium difficile causes life-threatening diarrhea and is the leading cause of healthcare-associated bacterial infections in the United States. TcdA and TcdB bacterial toxins are primary determinants of disease pathogenesis and are attractive therapeutic targets. TcdA and TcdB contain domains that use UDP-glucose to glucosylate and inactivate host Rho GTPases, resulting in cytoskeletal changes causing cell rounding and loss of intestinal integrity. Transition state analysis revealed glucocationic character for the TcdA and TcdB transition states. We identified transition state analogue inhibitors and characterized them by kinetic, thermodynamic and structural analysis. Iminosugars, isofagomine and noeuromycin mimic the transition state and inhibit both TcdA and TcdB by forming ternary complexes with Tcd and UDP, a product of the TcdA- and TcdB-catalyzed reactions. Both iminosugars prevent TcdA- and TcdB-induced cytotoxicity in cultured mammalian cells by preventing glucosylation of Rho GTPases. Iminosugar transition state analogues of the Tcd toxins show potential as therapeutics for C. difficile pathology.

PubMed: 34725358
DOI: 10.1038/s41467-021-26580-6

Experimental method

X-RAY DIFFRACTION (1.82 Å)