Acta Crystallographica Section F

Structural Biology and Crystallization Communications

Volume 61, Part 6 (June 2005)

crystallization communications

Acta Cryst. (2005). F61, 591-594 [ doi:10.1107/S1744309105015642 ]

Expression, purification, crystallization and preliminary X-ray analysis of a nucleoside kinase from the hyperthermophile Methanocaldococcus jannaschii

L. Arnfors, T. Hansen, W. Meining, P. Schönheit and R. Ladenstein

Abstract: Methanocaldococcus jannaschii nucleoside kinase (MjNK) is an ATP-dependent non-allosteric phosphotransferase that shows high catalytic activity for guanosine, inosine and cytidine. MjNK is a member of the phosphofructokinase B family, but participates in the biosynthesis of nucleoside monophosphates rather than in glycolysis. MjNK was crystallized as the apoenzyme as well as in complex with an ATP analogue and Mg²⁺. The latter crystal form was also soaked with fructose-6-phosphate. Synchrotron-radiation data were collected to 1.70 Å for the apoenzyme crystals and 1.93 Å for the complex crystals. All crystals exhibit orthorhombic symmetry; however, the apoenzyme crystals contain one monomer per asymmetric unit whereas the complex crystals contain a dimer.

Keywords: Methanocaldococcus jannaschii; phosphofructokinase B family; ribokinase superfamily; nucleoside kinases; hyperthermophiles; archaea.