Related Experiment Video
Updated: Jul 7, 2026

Measuring Lactase Enzymatic Activity in the Teaching Lab
Published on: August 6, 2018
Galactokinase: structure, function and role in type II galactosemia
H M Holden1, J B Thoden, D J Timson
1Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, USA. hazel_holden@biochem.wisc.edu.
Abstract:
The conversion of beta- D-galactose to glucose 1-phosphate is accomplished by the action of four enzymes that constitute the Leloir pathway. Galactokinase catalyzes the second step in this pathway, namely the conversion of alpha- D-galactose to galactose 1-phosphate. The enzyme has attracted significant research attention because of its important metabolic role, the fact that defects in the human enzyme can result in the diseased state referred to as galactosemia, and most recently for its utilization via 'directed evolution' to create new natural and unnatural sugar 1-phosphates. Additionally, galactokinase-like molecules have been shown to act as sensors for the intracellular concentration of galactose and, under suitable conditions, to function as transcriptional regulators. This review focuses on the recent X-ray crystallographic analyses of galactokinase and places the molecular architecture of this protein in context with the extensive biochemical data that have accumulated over the last 40 years regarding this fascinating small molecule kinase.
More Related Videos
Related Concept Videos
Oligosaccharide Assembly
Multiple sugar molecules that may or may...
Lysosomal Hydrolases
Glucose Transporters
Facilitated diffusion-glucose transporters (GLUTs) are encoded by the solute-linked carrier (SLC) family 2, subfamily A gene family, or SLC2A. The 14 GLUT protein members are distributed into three classes:
Proteoglycans
Inborn Errors of Metabolism
Inducible Operons: lac Operon

