title: Two ginseng UDP-glycosyltransferases synthesize ginsenoside Rg3 and Rd.
abstract: Ginseng is a medicinal herb that requires cultivation under shade conditions, typically for 4-6 years, before harvesting. The principal components of ginseng are ginsenosides, glycosylated tetracyclic terpenes. Dammarene-type ginsenosides are classified into two groups, protopanaxadiol (PPD) and protopanaxatriol (PPT), based on their hydroxylation patterns, and further diverge to diverse ginsenosides through differential glycosylation. Three early enzymes, dammarenediol-II synthase (DS) and two P450 enzymes, protopanaxadiol synthase (PPDS) and protopanaxatriol synthase (PPTS), have been reported, but glycosyltransferases that are necessary to synthesize specific ginsenosides have not yet been fully identified. To discover glycosyltransferases responsible for ginsenoside biosynthesis, we sequenced and assembled the ginseng transcriptome de novo and characterized two UDP-glycosyltransferases (PgUGTs): PgUGT74AE2 and PgUGT94Q2. PgUGT74AE2 transfers a glucose moiety from UDP-glucose (UDP-Glc) to the C3 hydroxyl groups of PPD and compound K to form Rh2 and F2, respectively, whereas PgUGT94Q2 transfers a glucose moiety from UDP-Glc to Rh2 and F2 to form Rg3 and Rd, respectively. Introduction of the two UGT genes into yeast together with PgDS and PgPPDS resulted in the de novo production of Rg3. Our results indicate that these two UGTs are key enzymes for the synthesis of ginsenosides and provide a method for producing specific ginsenosides through yeast fermentation.
authors.affiliation: Department of Biological Sciences, KAIST, Daejeon 305-701, Republic of Korea.
authors.forename: Suk-Chae
authors.initials: SC
authors.lastname: Jung
authors.affiliation: Department of Biological Sciences, KAIST, Daejeon 305-701, Republic of Korea.
authors.forename: Woohyun
authors.initials: W
authors.lastname: Kim
authors.affiliation: Department of Biological Sciences, KAIST, Daejeon 305-701, Republic of Korea.
authors.forename: Sung Chul
authors.initials: SC
authors.lastname: Park
authors.affiliation: Department of Biological Sciences, KAIST, Daejeon 305-701, Republic of Korea.
authors.forename: Jinkil
authors.initials: J
authors.lastname: Jeong
authors.affiliation: Department of Biological Sciences, KAIST, Daejeon 305-701, Republic of Korea.
authors.forename: Myung Keun
authors.initials: MK
authors.lastname: Park
authors.affiliation: Department of Biological Sciences, KAIST, Daejeon 305-701, Republic of Korea.
authors.forename: Soohwan
authors.initials: S
authors.lastname: Lim
authors.affiliation: Department of Biological Sciences, KAIST, Daejeon 305-701, Republic of Korea.
authors.forename: Yeon
authors.initials: Y
authors.lastname: Lee
authors.affiliation: KAIST Institute for Biocentury, KAIST, Daejeon, 305-701, Republic of Korea.
authors.forename: Wan-Taek
authors.initials: WT
authors.lastname: Im
authors.affiliation: KAIST Institute for Biocentury, KAIST, Daejeon, 305-701, Republic of Korea.
authors.forename: Jun Hyoung
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Biological Sciences, KAIST, Daejeon 305-701, Republic of Korea gchoi@kaist.ac.kr sunkim@kaist.ac.kr.
authors.forename: Giltsu
authors.initials: G
authors.lastname: Choi
authors.affiliation: Department of Biological Sciences, KAIST, Daejeon 305-701, Republic of Korea gchoi@kaist.ac.kr sunkim@kaist.ac.kr.
authors.forename: Sun Chang
authors.initials: SC
authors.lastname: Kim
mesh_terms: D036145:Ginsenosides / Q000378:metabolism*; D016695:Glycosyltransferases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D005894:Panax / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000737:chemistry / Q000201:enzymology / Q000235:genetics; D010946:Plants, Medicinal; D012502:Sapogenins / Q000378:metabolism
chemical_list: D036145:Ginsenosides; D016695:Glycosyltransferases; D010940:Plant Proteins; D012502:Sapogenins; C097367:ginsenoside Rg3; C081552:protopanaxatriol; C112772:ginsenoside compound K; C062916:protopanaxadiol
keywords: Ginsenoside biosynthesis; Panax ginseng; UDP-glycosyltransferase; UGT74; UGT94; Yeast