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: Yusuke Ono, Atsushi Minami, Motoyoshi Noike, Yusuke Higuchi, Tomonobu Toyomasu, Takeshi Sassa, Nobuo Kato, Tohru Dairi
• Journal: Journal of the American Chemical Society (J Am Chem Soc) Vol. 133 Issue 8 Pg. 2548-55 (Mar 02 2011) ISSN: 1520-5126 [Electronic] United States
• PMID: 21299202 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Diterpenes
• Glycosides
• brassicicene C
• cotylenin A
• fusicoccin
• Dioxygenases

Topics

• Alternaria (enzymology, metabolism)
• Amino Acid Sequence
• Ascomycota (enzymology, metabolism)
• Biocatalysis
• Dioxygenases (chemistry, genetics, metabolism)
• Diterpenes (chemistry, metabolism)
• Glycosides (biosynthesis, chemistry)
• Molecular Sequence Data
• Sequence Alignment