Expression in Escherichia coli of a recombinant adenosine kinase from Saccharomyces cerevisiae: purification, kinetics and substrate analyses.

The Saccharomyces cerevisiae ADO1 gene is known to encode a homologue of eukaryotic adenosine kinases. This gene was expressed in Escherichia coli as a recombinant protein fused to a polyhistidine tag by using the rhamnose-inducible bacterial promoter rhaB. The recombinant protein was purified to apparent homogeneity and its ability to phosphorylate different substrates was evaluated. Adenosine (Km 3 microM) is its primary substrate. In addition, it also phosphorylates, albeit less efficiently, 3'-deoxyadenosine (cordycepin; Km 1.84 mM) and 3'-amino-3'-deoxyadenosine (Km 0.26 mM). Other kinetic properties of the recombinant enzyme have also been determined.