Seems bifunctional with both a galactokinase activity and the ability to induce the GAL genes. alpha-D-galactose + ATP = ADP + alpha-D-galactose 1-phosphate + H(+) Carbohydrate metabolism; galactose metabolism. The GAL1 gene is a member of the family of galactose inducible, glucose-repressible genes (which include GAL2, GAL3, GAL7, GAL10, GAL80, and MELI). Belongs to the GHMP kinase family. GalK subfamily.