The β-glucosidase gene has important effects on alcoholic aroma precursors and insect resistance of the tea plant [Camellia sinensis (L.) O. Kutze]. The complete cDNA sequence of β-glucosidase of the tea plant was cloned; its full length was 1475 bp, and shared 40–60% similarity with corresponding parts of the nucleotide sequence of β-glucosidase gene from other plants. Its secondary structure contains 14.33% α-helix, 25.43% β-pleated sheet and many functional amino acid domains. The β-glucosidase gene was cloned into the pET-32a expression system and expressed at high-efficiently in Escherichia coli BL21 (DE3); the molecular weight of expressed fusion protein was 63 kDa. The results of enzymic reaction showed that the fusion protein possessed normal bioactivity, and it could catalyse the dehydration of the glycosidic bond. The soluble fusion protein was expressed mainly in the cytoplasm.
