Browsing by Author "Kwon, Moonhyuk"

Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    A chromosome level reference genome of Diviner’s sage (Salvia divinorum) provides insight into salvinorin A biosynthesis
    (2024-10-01) Ford, Scott A.; Ness, Rob W.; Kwon, Moonhyuk; Ro, Dae-Kyun; Phillips, Michael A.
    Abstract Background Diviner’s sage (Salvia divinorum; Lamiaceae) is the source of the powerful hallucinogen salvinorin A (SalA). This neoclerodane diterpenoid is an agonist of the human Κ-opioid receptor with potential medical applications in the treatment of chronic pain, addiction, and post-traumatic stress disorder. Only two steps of the approximately twelve step biosynthetic sequence leading to SalA have been resolved to date. Results To facilitate pathway elucidation in this ethnomedicinal plant species, here we report a chromosome level genome assembly. A high-quality genome sequence was assembled with an N50 value of 41.4 Mb and a BUSCO completeness score of 98.4%. The diploid (2n = 22) genome of ~ 541 Mb is comparable in size and ploidy to most other members of this genus. Two diterpene biosynthetic gene clusters were identified and are highly enriched in previously unidentified cytochrome P450s as well as crotonolide G synthase, which forms the dihydrofuran ring early in the SalA pathway. Coding sequences for other enzyme classes with likely involvement in downstream steps of the SalA pathway (BAHD acyl transferases, alcohol dehydrogenases, and O-methyl transferases) were scattered throughout the genome with no clear indication of clustering. Differential gene expression analysis suggests that most of these genes are not inducible by methyl jasmonate treatment. Conclusions This genome sequence and associated gene annotation are among the highest resolution in Salvia, a genus well known for the medicinal properties of its members. Here we have identified the cohort of genes responsible for the remaining steps in the SalA pathway. This genome sequence and associated candidate genes will facilitate the elucidation of SalA biosynthesis and enable an exploration of its full clinical potential.
  • Thumbnail Image
    ItemOpen Access
    Piperonal synthase from black pepper (Piper nigrum) synthesizes a phenolic aroma compound, piperonal, as a CoA-independent catalysis
    (2022-03-24) Jin, Zhehao; Ro, Dae-Kyun; Kim, Soo-Un; Kwon, Moonhyuk
    Abstract Piperonal is a simple aromatic aldehyde compound with a characteristic cherry-like aroma and has been widely used in the flavor and fragrance industries. Despite piperonal being an important aroma in black pepper (Piper nigrum), its biosynthesis remains unknown. In this study, the bioinformatic analysis of the P. nigrum transcriptome identified a novel hydratase-lyase, displaying 72% amino acid identity with vanillin synthase, a member of the cysteine proteinase family. In in vivo substrate-feeding and in vitro enzyme assays, the hydratase-lyase catalyzed a side-chain cleavage of 3,4-methylenedioxycinnamic acid (3,4-MDCA) to produce 3,4-methylenedioxybenzaldehyde (piperonal) and thus was named piperonal synthase (PnPNS). The optimal pH for PnPNS activity was 7.0, and showed a Km of 317.2 μM and a kcat of 2.7 s−1. The enzyme was most highly expressed in the leaves, followed by the fruit. This characterization allows for the implementation of PnPNS in various microbial platforms for the biological production of piperonal.