Figure 5. The amino acid sequences of the three OSCs cloned from M. ilicifolia leaves.

Four conserved QW motifs and the catalytic site DCTAE are underlined, indicating the acids involved in substrate carbocation formation. Other conserved residues in the OSCs are MXCH/YCR, which are delimited by a dashed line, and the residues GYN and SF that differentiate tetracyclic to pentacyclic synthases, which are double underlined.