title: Dioxygenases, key enzymes to determine the aglycon structures of fusicoccin and brassicicene, diterpene compounds produced by fungi.
abstract: Fusicoccin A and cotylenin A are structurally related diterpene glucosides and show a phytohormone-like activity. However, only cotylenin A induces the differentiation of human myeloid leukemia cells. Since the cotylenin A producer lost its ability to proliferate during preservation, a study on the relationship between structure and activity was carried out and a modified fusicoccin A with hydroxyl group at the 3-position showed a similar biological activity with that of cotylenin A. We then searched for an enzyme source that catalyzes the introduction of a hydroxyl group into the 3-position and found that brassicicene C, which is structurally related to fusicoccin A with hydroxyl group at the 3-position, was produced by Alternaria brassicicola ATCC96836. We recently cloned a brassicicene C biosynthetic gene cluster including the genes encoding fusicocca-2,10(14)-diene synthase and two cytochrome P450s, which were responsible for the formation of fusicocca-2,10(14)-diene-8β,16-diol. In this study, we report that a α-ketoglutarate dependent dioxygenase, the gene coding for which was located in the cluster, catalyzed a hydroxylation at the 3-position of fusicocca-2,10(14)-diene-8β,16-diol. On the other hand, a α-ketoglutarate-dependent dioxygenase, which had been identified in a fusicoccin A biosynthetic gene cluster, catalyzed the 16-oxidation of fusicocca-2,10(14)-diene-8β,16-diol to yield an aldehyde (8β-hydroxyfusicocca-1,10(14)-dien-16-al), although both dioxygenases had 51% amino acid sequence identity. These findings suggested that the dioxygenases played critical roles for the formation of the fusicoccin A-type and cotylenin A-/brassicicene C-type aglycons. Moreover, we showed that short-chain dehydrogenase/reductase located in the fusicoccin A biosynthetic gene cluster catalyzed the reduction of the aldehyde to yield fusicocca-1,10(14)-diene-8β,16-diol.
authors.affiliation: Graduate School of Engineering, Hokkaido University, Hokkaido, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ono
authors.forename: Atsushi
authors.initials: A
authors.lastname: Minami
authors.forename: Motoyoshi
authors.initials: M
authors.lastname: Noike
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Higuchi
authors.forename: Tomonobu
authors.initials: T
authors.lastname: Toyomasu
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sassa
authors.forename: Nobuo
authors.initials: N
authors.lastname: Kato
authors.forename: Tohru
authors.initials: T
authors.lastname: Dairi
mesh_terms: D000528:Alternaria / Q000201:enzymology / Q000378:metabolism; D000595:Amino Acid Sequence; D001203:Ascomycota / Q000201:enzymology / Q000378:metabolism; D055162:Biocatalysis; D049308:Dioxygenases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004224:Diterpenes / Q000737:chemistry* / Q000378:metabolism*; D006027:Glycosides / Q000096:biosynthesis* / Q000737:chemistry; D008969:Molecular Sequence Data; D016415:Sequence Alignment
chemical_list: D004224:Diterpenes; D006027:Glycosides; C539991:brassicicene C; C423222:cotylenin A; C007808:fusicoccin; D049308:Dioxygenases