文献类型：期刊文献

英文题名：Genetic, molecular, and biochemical basis of fungal tropolone biosynthesis

作者：Davison, Jack[1];al Fahad, Ahmed[1];Cai, Menghao[2];Song, Zhongshu[1];Yehia, Samar Y.[3];Lazarus, Colin M.[4];Bailey, Andrew M.[4];Simpson, Thomas J.[1];Cox, Russell J.[1]

机构：[1]Univ Bristol, Sch Chem, Bristol BS8 1TS, Avon, England;[2]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[3]Future Univ Egypt, Fac Pharmaceut Sci & Pharmaceut Ind, New Cairo 11477, Egypt;[4]Univ Bristol, Sch Biol Sci, Bristol BS8 1UG, Avon, England

年份：2012

卷号：109

期号：20

起止页码：7642

外文期刊名：PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000304369800025)】；

基金：We thank the Engineering and Physical Sciences Research Council for Grant EP/F066104/1 (J.D. studentship, Z.S. funding, LCMS equipment); Al Baha University, Saudi Arabia (A.a.F. studentship); the Egyptian Cultural Centre London (S.Y.Y. visiting fellowship); China Scholarship Council (M.C., visiting studentship); and Dr. Mairi Haddow for assistance with X-ray crystallography.

语种：英文

外文关键词：oxidative rearrangement; azaphilone; colchicine

摘要：A gene cluster encoding the biosynthesis of the fungal tropolone stipitatic acid was discovered in Talaromyces stipitatus (Penicillium stipitatum) and investigated by targeted gene knockout. A minimum of three genes are required to form the tropolone nucleus: tropA encodes a nonreducing polyketide synthase which releases 3-methylorcinaldehyde; tropB encodes a FAD-dependent monooxygenase which dearomatizes 3-methylorcinaldehyde via hydroxylation at C-3; and tropC encodes a non-heme Fe(II)-dependent dioxygenase which catalyzes the oxidative ring expansion to the tropolone nucleus via hydroxylation of the 3-methyl group. The tropA gene was characterized by heterologous expression in Aspergillus oryzae, whereas tropB and tropC were successfully expressed in Escherichia coli and the purified TropB and TropC proteins converted 3-methylorcinaldehyde to a tropolone in vitro. Finally, knockout of the tropD gene, encoding a cytochrome P450 monooxygenase, indicated its place as the next gene in the pathway, probably responsible for hydroxylation of the 6-methyl group. Comparison of the T. stipitatus tropolone biosynthetic cluster with other known gene clusters allows clarification of important steps during the biosynthesis of other fungal compounds including the xenovulenes, citrinin, sepedonin, sclerotiorin, and asperfuranone.