The cDNA clone for strictosidine synthase from Rauvolfia serpentina DNA sequence determination and expression in Escherichia coli

The cDNA clone for strictosidine synthase, the enzyme which catalyzes the stereospecific condensation of tryptamine with secologanin to form the key intermediate in indole alkaloid biosynthesis, strictosidine, has been identified with a synthetic oligodeoxynucleotide hybridization probe in a λgt11 cDNA library of cultured cells of Rauvolfia serpentina. The DNA has been sequenced, revealing an open reading frame of 1032 base pairs encoding 344 amino acids. The sequence of 60 nucleotides in the 5′-flanking region has been determined by primer extension analysis. The encoded protein has been expressed in E. coli DH5 as detected by immunoblotting of protein extracts with antibodies raised against the native enzyme.