A highly conserved sequence is a novel gene involved inde novovitamin B6 biosynthesis

Marilyn Ehrenshaft1, Piotr Bilski1, Ming Y. Li1, Colin F. Chignell1, Margaret E. Daub1
1Departments of Plant Pathology and Chemistry, North Carolina State University, Raleigh, NC 27695; and Laboratory of Pharmacology and Chemistry, National Institute for Environmental Health Sciences, Research Triangle Park, NC 27709

Tóm tắt

TheCercospora nicotianae SOR1(singlet oxygen resistance) gene was identified previously as a gene involved in resistance of this fungus to singlet-oxygen-generating phototoxins. Although homologues toSOR1occur in organisms in four kingdoms and encode one of the most highly conserved proteins yet identified, the precise function of this protein has, until now, remained unknown. We show thatSOR1is essential in pyridoxine (vitamin B6) synthesis inC. nicotianaeandAspergillus flavus,although it shows no homology to previously identified pyridoxine synthesis genes identified inEscherichia coli. Sequence database analysis demonstrated that organisms encode eitherSOR1orE. colipyridoxine biosynthesis genes, but not both, suggesting that there are two divergent pathways forde novopyridoxine biosynthesis in nature. Pathway divergence appears to have occurred during the evolution of the eubacteria. We also present data showing that pyridoxine quenches singlet oxygen at a rate comparable to that of vitamins C and E, two of the most highly efficient biological antioxidants, suggesting a previously unknown role for pyridoxine in active oxygen resistance.

Từ khóa


Tài liệu tham khảo

10.1111/j.1751-1097.1995.tb02350.x

M E Daub, M Ehrenshaft, A E Jenns, K R Chung Phytochemical Signals and Plant-Microbe Interactions, Recent Advances in Phytochemistry, eds K R Downum, R Verpoorte (Plenum, New York) 32, 31–56 (1998).

10.1007/978-1-4615-8061-4_3

10.1094/Phyto-85-906

10.1016/S1097-2765(00)80060-X

10.1007/s002940050423

10.1128/jb.178.23.6865-6872.1996

10.1046/j.1365-2958.1997.3671706.x

R E Hill, I D Spenser Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology, eds F C Neidhardt, R Curtiss, J L Ingraham, E C C Lin, K B Low, B Magasanik, W S Reznikoff, M Riley, M Schaechter, H E Umbarger (Am. Soc. Microbiol., Washington, DC) 1, 695–703 (1996).

10.1128/jb.172.11.6518-6528.1990

G Zhao, M E Winkler FEMS Microbiol Lett 135, 275–280 (1996).

10.1128/JB.180.16.4294-4299.1998

10.1099/00221287-110-2-275

10.1016/0014-5793(96)00652-7

10.1094/Phyto-79-213

10.1128/aem.55.1.86-90.1989

P J Punt, N D Zegers, M Busscher, P H Pouwels, C A M J J van den Hondel Biotechnology 17, 19–24 (1991).

10.1016/S0022-2836(05)80360-2

10.1016/S0165-022X(96)00012-7

10.1094/Phyto-72-370

10.1128/jb.171.9.4767-4777.1989

10.1128/jb.171.11.6084-6092.1989

10.1128/jb.174.5.1554-1567.1992

D Bellus Adv Photochem 11, 105–205 (1979).

10.1063/1.555965

10.1016/S0006-291X(83)80024-2

10.3109/10715769009053358

10.1111/j.1751-1097.1979.tb09255.x

10.1021/j100220a004

10.1111/j.1751-1097.1993.tb02317.x

10.1016/1011-1344(91)80031-C

10.1111/j.1751-1097.1994.tb05035.x

10.1016/0304-4165(94)00205-C

K Tazuya, K Yamada, H Kumaoka Biochem Mol Biol Int 30, 893–899 (1993).

10.1128/JB.180.21.5718-5726.1998

10.1007/BF00019129

10.1034/j.1399-3054.1996.980219.x

10.1080/13510002.1995.11746964

10.1101/gad.5.1.60

10.1101/gad.12.10.1453

10.1111/j.1365-2958.1995.tb02407.x

10.1002/j.1460-2075.1994.tb06304.x