Cloning, analysis and expression of the gene for β-glycosidase of Thermus caldophilus GK24 and properties of the enzyme

The gene (bglT) encoding Thermus caldophilus GK24 β-glycosidase (Tca β-glycosidase) was cloned and sequenced. The gene contains an open reading frame encoding 431 amino acids with a Mr of 48 658 Da. The bglT gene was expressed under the control of tac promoter on a high-copy plasmid in E. coli. The recombinant Tca β-glycosidase was purified 41.5-fold with a 59% yield and a specific activity of 83 U mg−1 protein.