A Highly Conserved Sequence Is a Novel Gene Involved in de novo Vitamin B6 Biosynthesis

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