Structural determination and kinetic analysis of the transketolase from Vibrio vulnificus reveal unexpected cooperative behavior.

Autor: Georges RN; Univ Lyon, Université Claude Bernard Lyon 1, Villeurbanne, France., Ballut L; Molecular Microbiology and Structural Biochemistry, UMR 5086, CNRS-Université de Lyon, Lyon, France., Octobre G; Univ Lyon, Université Claude Bernard Lyon 1, Villeurbanne, France., Comte A; Univ Lyon, Université Claude Bernard Lyon 1, Villeurbanne, France., Hecquet L; Université Clermont Auvergne, CNRS, SIGMA Clermont, Institut de Chimie de Clermont-Ferrand (ICCF), Clermont-Ferrand, France., Charmantray F; Université Clermont Auvergne, CNRS, SIGMA Clermont, Institut de Chimie de Clermont-Ferrand (ICCF), Clermont-Ferrand, France., Doumèche B; Univ Lyon, Université Claude Bernard Lyon 1, Villeurbanne, France.
Jazyk: angličtina
Zdroj: Protein science : a publication of the Protein Society [Protein Sci] 2024 Mar; Vol. 33 (3), pp. e4884.
DOI: 10.1002/pro.4884
Abstrakt: Vibrio vulnificus (vv) is a multidrug-resistant human bacterial pathogen whose prevalence is expected to increase over the years. Transketolases (TK), transferases catalyzing two reactions of the nonoxidative branch of the pentose-phosphate pathway and therefore linked to several crucial metabolic pathways, are potential targets for new drugs against this pathogen. Here, the vvTK is crystallized and its structure is solved at 2.1 Å. A crown of 6 histidyl residues is observed in the active site and expected to participate in the thiamine pyrophosphate (cofactor) activation. Docking of fructose-6-phosphate and ferricyanide used in the activity assay, suggests that both substrates can bind vvTK simultaneously. This is confirmed by steady-state kinetics showing a sequential mechanism, on the contrary to the natural transferase reaction which follows a substituted mechanism. Inhibition by the I38-49 inhibitor (2-(4-ethoxyphenyl)-1-(pyrimidin-2-yl)-1H-pyrrolo[2,3-b]pyridine) reveals for the first time a cooperative behavior of a TK and docking experiments suggest a previously undescribed binding site at the interface between the pyrophosphate and pyridinium domains.
(© 2023 The Protein Society.)
Databáze: MEDLINE
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