title: The Pdx1 family is structurally and functionally conserved between Arabidopsis thaliana and Ginkgo biloba.
abstract: Vitamin B6 is one of the most important compounds in living organisms, and its biosynthesis has only recently been understood. Because it is required for more than 100 biochemical reactions, lack of the vitamin is fatal. This is of special importance to mammals and humans, which cannot biosynthesize the vitamin and thus depend on its external uptake. Here we describe the cloning of a vitamin B6 biosynthetic gene GbPDX1 from Ginkgo biloba. The gene is expressed in seeds, leaf and trunk tissue. Using yeast 2-hybrid and pull-down assays, we show that the protein can interact with itself and with members of Arabidopsis thaliana AtPDX1 and AtPDX2 families. Furthermore, we prove the function of GbPDX1 in vitamin B6 biosynthesis by complementation of an Arabidopsis AtPDX1.3 mutant rsr4-1, at the phenotypical level and increasing vitamin B6 levels caused by ectopic GbPDX1 expression in the mutant background. Overall, this study provides a first description of Ginkgo vitamin B6 metabolism, and demonstrates a high degree of conservation between Ginkgo and Arabidopsis.
authors.affiliation: Angewandte Genetik, Freie Universität, Berlin, Germany.
authors.forename: Jan E
authors.initials: JE
authors.lastname: Leuendorf
authors.forename: Andreas
authors.initials: A
authors.lastname: Genau
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Szewczyk
authors.forename: Sutton
authors.initials: S
authors.lastname: Mooney
authors.forename: Christel
authors.initials: C
authors.lastname: Drewke
authors.forename: Eckhard
authors.initials: E
authors.lastname: Leistner
authors.forename: Hanjo
authors.initials: H
authors.lastname: Hellmann
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019759:Carbon-Nitrogen Lyases; D003001:Cloning, Molecular; D017124:Conserved Sequence; D005816:Genetic Complementation Test; D020441:Ginkgo biloba / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D019884:Nitrogenous Group Transferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D025101:Vitamin B 6 / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D010940:Plant Proteins; D025101:Vitamin B 6; D019884:Nitrogenous Group Transferases; D019759:Carbon-Nitrogen Lyases; C505161:At2g38230 protein, Arabidopsis