Title
Catalytic properties and crystal structure of UDP-galactose 4-epimerase-like l-threonine 3-dehydrogenase from Phytophthora infestans
Author
Kazunari Yoneda, Rina Nagano, Takuya Mikami, Haruhiko Sakuraba, Kenji Fukui, Tomohiro Araki, Toshihisa Ohshima
Year
2020
Journal
Enzyme and Microbial Technology
Abstract
We report, for the first time, the three-dimensional structure and biochemical properties of a UDP-galactose 4-epimerase-like l-threonine 3-dehydrogenase (GalE-like L-ThrDH) from Phytophthora infestans, a plant disease-causing fungus. We identified GalE-like L-ThrDH using Kyoto Encyclopedia of Genes and Genomes (KEGG) database as a candidate target for the development of a new fungicide. The GalE-like L-ThrDH gene was expressed in Escherichia coli, and its product was purified and characterized. N-Acetylglycine was found to act as a competitive inhibitor of the enzyme (Ki =0.18 mM). The crystal structure of the unique hexameric GalE-like L-ThrDH was determined using the molecular replacement method at a resolution of 2.3 Å, in the presence of NAD+ and citrate, an analogue of the substrate. Based on the molecular docking simulation, N-acetylglycine molecule was modeled into the active site and the binding mode and inhibition mechanism of N-acetylglycine were elucidated.
Instrument
J-820
Keywords
Circular dichroism, Secondary structure, Biochemistry