The characterisation of a galactokinase from Streptomyces coelicolor.

Affiliation

Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK. Electronic address: [Email]

Abstract

Promiscuous galactokinases (GalKs), which catalyse the ATP dependent phosphorylation of galactose in nature, have been widely exploited in biotechnology for the rapid synthesis of diverse sugar-1-phosphates. This work focuses on the characterisation of a bacterial GalK from Streptomyces coelicolor (ScGalK), which was overproduced in Escherichia coli and shown to phosphorylate galactose. ScGalK displayed a broad substrate tolerance, with activity towards Gal, GalN, Gal3D, GalNAc, Man and L-Ara. Most interestingly, ScGalK demonstrated a high activity over a broad pH and temperature range, suggesting that the enzyme could be highly amenable to multi-enzyme systems.

Keywords

Galactokinase,Streptomyces coelicolor,Substrate specificity,Sugar-1-phosphates,