Function
Galactokinase (GALK) is the enzyme which catalyzes the second step in the Leloir pathway which converts β-D-galactose to glucose 1-phosphate. GALK catalyzes the conversion of α-D-galactose to galactose 1-phosphate[1].
Disease
Hereditary GALK deficiency is called galactosemia. The symptoms are early onset of cataract and impairment of galactose (gal) metabolism[2]..
Structural highlights
The 3D structure of human GALK shows the sugar binding active site wedged between the N- and C-termini of the enzyme. The galactose forms with GALK termini residues and in particular forms hydrogen bonds with an Asp and Arg residues which are conserved in eukaryotic and prokaryotic GALK[3].
3D structures of galactokinase
Updated on 14-October-2020
6gr2 - hGALK + ADP + gal - human
1wuu - hGALK + Mg + AMPPNP + gal
6q3w, 6q8z - hGALK + pyrazine derivative + gal
6q91 - hGALK + benzamide derivative + gal
6q90, 6zgw - hGALK + pyridine derivative + gal
6q3x - hGALK + quinazoline derivative + gal
6zgv, 6zgx, 6zgz, 6zgy - hGALK + pyrimidine derivative + gal
6qje - hGALK + imidazole derivative + gal
2aj4 - GALK + Mg + AMPPNP + gal - yeast
1s4e - GALK + Mg + ADP + gal - Pyrococcus furiosus
2dej, 2dei - GALK + AMPPN derivative + gal - Pyrococcus horikoshii
1pie - GALK + gal - Lactococcus lactis
6tep - BiGALK + Mg + ADP - Bifidobacterium infantis
6ter, 6teq - BiGALK + gal derivative
