Component of the dammarane-type triterpene saponins (e.g. ginsenosides or panaxosides) biosynthetic pathway (PubMed:22039120, PubMed:25981048, PubMed:27746309, PubMed:29378087). Catalyzes the hydroxylation of dammarenediol-II at the C-12 position to yield protopanaxadiol in ginsenoside biosynthesis, a class of tetracyclic triterpenoid saponins (PubMed:22039120, PubMed:25981048). dammarenediol-II + O2 + reduced [NADPH--hemoprotein reductase] = (20S)-protopanaxadiol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (20S)-20-O-(beta-D-glucosyl)-3-hydroxydammarene + O2 + reduced [NADPH--hemoprotein reductase] = (20S)-ginsenoside C-K + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] Secondary metabolite biosynthesis; terpenoid biosynthesis. Accumulates ubiquitously in all organs of plants (PubMed:22875608). Mostly expressed in leaves and flowers, and, to a lower extent, in roots and stems (PubMed:24603359, PubMed:30577538). Rapid decrease in leaves from the leaf opened to the green fruit stage (PubMed:30577538). Rapid and transient increase in roots from the leaf opened to the green fruit stage (PubMed:30577538). Up-regulated by methyl jasmonate (MeJA) (PubMed:22039120, PubMed:22875608). Induced by A.niger mycelium-derived elicitor, thus improving ginsenosides production in adventitious roots culture (PubMed:27746309). Slightly induced by Tween 80 (PubMed:24889095). Influenced in roots by soil water potential, and in leaves by temperature, rain and relative humidity (PubMed:30577538). Transgenic tobacco plants coexpressing PgDDS and PgPPDS1/CYP716A47 accumulate dammarene sapogenin (protopanaxadiol, PPD). Belongs to the cytochrome P450 family. Truncated N-terminus.