title: Crystallization and preliminary X-ray diffraction analysis of L-threonine dehydrogenase (TDH) from the hyperthermophilic archaeon Thermococcus kodakaraensis.
abstract: The enzyme L-threonine dehydrogenase catalyses the NAD(+)-dependent conversion of L-threonine to 2-amino-3-ketobutyrate, which is the first reaction of a two-step biochemical pathway involved in the metabolism of threonine to glycine. Here, the crystallization and preliminary crystallographic analysis of L-threonine dehydrogenase (Tk-TDH) from the hyperthermophilic organism Thermococcus kodakaraensis KOD1 is reported. This threonine dehydrogenase consists of 350 amino acids, with a molecular weight of 38 kDa, and was prepared using an Escherichia coli expression system. The purified native protein was crystallized using the hanging-drop vapour-diffusion method and crystals grew in the tetragonal space group P4(3)2(1)2, with unit-cell parameters a = b = 124.5, c = 271.1 A. Diffraction data were collected to 2.6 A resolution and preliminary analysis indicates that there are four molecules in the asymmetric unit of the crystal.
authors.affiliation: School of Biological Sciences, University of Southampton, Southampton SO16 7PX, England.
authors.forename: A
authors.initials: A
authors.lastname: Bowyer
authors.forename: H
authors.initials: H
authors.lastname: Mikolajek
authors.forename: J N
authors.initials: JN
authors.lastname: Wright
authors.forename: A
authors.initials: A
authors.lastname: Coker
authors.forename: P T
authors.initials: PT
authors.lastname: Erskine
authors.forename: J B
authors.initials: JB
authors.lastname: Cooper
authors.forename: Q
authors.initials: Q
authors.lastname: Bashir
authors.forename: N
authors.initials: N
authors.lastname: Rashid
authors.forename: F
authors.initials: F
authors.lastname: Jamil
authors.forename: M
authors.initials: M
authors.lastname: Akhtar