Supplemental Figure S1. Alignment of drimenol synthase amino acid sequences from P. hydropiper and V. officinalis. Amino acid sequences were aligned with ClustalW (http://www.ch.embnet.org/software/ClustalW.html). Identical and similar residues are shaded black and gray, respectively; aspartate-rich motif DDxxD are indicated in red-colored box, the latter one involved in binding of the magnesium ion and corresponds to the class I type of cyclization. The function of the other one located more upstream is unknown, but could possibly be involved in a protonation type cyclization, which has been proposed by Kwon et al. (2014).