Biosynthesis of 4‘-<i>O</i>-Methylpyridoxine (Ginkgotoxin) from Primary Precursors

Fiehe, K.; Arenz, Ansgar; Drewke, Christel; Hemscheidt, Thomas; Williamson, R. Thomas; Leistner, Eckhard

doi:10.1021/np990414+

Cited by 30 publications

(33 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Based on the northern blot analysis of the tested tissues, expression of GbPDX1 is highest in seeds. This is consistent with previous work on the ginkgotoxin, which was found to be in the highest concentration in seeds [35,37], and one might expect a correlating biosynthetic activity of vitB6 as the precursor of ginkgotoxin [2].…”

Section: Discussionsupporting

confidence: 93%

The Pdx1 family is structurally and functionally conserved between Arabidopsis thaliana and Ginkgo biloba

Leuendorf¹,

Genau²,

Szewczyk³

et al. 2008

The FEBS Journal

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: Discussionsupporting

confidence: 93%

The Pdx1 family is structurally and functionally conserved between Arabidopsis thaliana and Ginkgo biloba

Leuendorf¹,

Genau²,

Szewczyk³

et al. 2008

The FEBS Journal

Self Cite

View full text Add to dashboard Cite

show abstract

“…The antibiotic bacimethrin is a structural thiamine (vitamin B 1 ) analog naturally produced by Bacillus megaterium and Streptomyces albus (49). Ginkgotoxin is a neurotoxin occurring in Ginkgo biloba and is structurally related to vitamin B 6 (pyridoxine) (13). The biosynthetic pathways for bacimethrin and ginkgotoxin are unknown.…”

Section: Discussionmentioning

confidence: 99%

Genome Sequence of the Bacterium Streptomyces davawensis JCM 4913 and Heterologous Production of the Unique Antibiotic Roseoflavin

et al. 2012

View full text Add to dashboard Cite

show abstract

“…Astonishingly, although plants are a major source of vitamin B6 in the human diet, our understanding of the pathway therein is very limited and has been assumed to be derived the same way as in E. coli. There is one preliminary study that reports on its biosynthesis in spinach (8), whereas other, more in-depth studies have addressed the topic based on the formation of 4Ј-O-methylpyridoxine, a vitamin B6 derivative found in Ginkgo biloba (9,10). Knowledge of the pathway in plants may not only aid in studies designed for overproduction of the vitamin for beneficial effects, but proteins involved could also provide novel herbicidal targets if proven to be essential for viability of the organism.…”

mentioning

confidence: 99%

Vitamin B6 biosynthesis in higher plants

Tambasco-Studart

Titiz²,

Raschle³

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

207

260

View full text Add to dashboard Cite

Vitamin B6 is an essential metabolite in all organisms. It can act as a coenzyme for numerous metabolic enzymes and has recently been shown to be a potent antioxidant. Plants and microorganisms have a de novo biosynthetic pathway for vitamin B6, but animals must obtain it from dietary sources. In Escherichia coli, it is known that the vitamin is derived from deoxyxylulose 5-phosphate (an intermediate in the nonmevalonate pathway of isoprenoid biosynthesis) and 4-phosphohydroxy-L-threonine. It has been assumed that vitamin B6 is synthesized in the same way in plants, but this hypothesis has never been experimentally proven. Here, we show that, in plants, synthesis of the vitamin takes an entirely different route, which does not involve deoxyxylulose 5-phosphate but instead utilizes intermediates from the pentose phosphate pathway, i.e., ribose 5-phosphate or ribulose 5-phosphate, and from glycolysis, i.e., dihydroxyacetone phosphate or glyceraldehyde 3-phosphate. The revelation is based on the recent discovery that, in bacteria and fungi, a novel pathway is in place that involves two genes (PDX1 and PDX2), neither of which is homologous to any of those involved in the previously doctrined E. coli pathway. We demonstrate that Arabidopsis thaliana has two functional homologs of PDX1 and a single homolog of PDX2. Furthermore, and contrary to what was inferred previously, we show that the pathway appears to be cytosolic and is not localized to the plastid. Last, we report that the single PDX2 homolog is essential for plant viability.Arabidopsis ͉ isoprenoid ͉ pyridoxine ͉ deoxyxylulose 5-phosphate V itamin B6 is well renowned in the medical field for being involved in more bodily functions than any other single nutrient. The vitamin exists in various forms, i.e., pyridoxal, pyridoxine, pyridoxamine, and their phosphorylated derivatives. As pyridoxal 5Ј-phosphate, it is an essential cofactor for numerous metabolic enzymes including amino acid metabolism and antibiotic biosynthesis. Most interestingly, it has recently been found that the vitamin is a potent antioxidant with a particular ability to quench reactive oxygen species such as superoxide and singlet oxygen (1, 2). The de novo biosynthesis of vitamin B6 takes place in microorganisms and plants, but this ability has been lost in animals, making it essential in the human diet.Despite the vitamin's obvious physiological and pharmaceutical importance, its biosynthesis has predominantly been studied in the Gram-negative bacterium, Escherichia coli, where it is derived from deoxyxylulose 5-phosphate (DXP, an intermediate in the nonmevalonate pathway of isoprenoid biosynthesis) and 4-phosphohydroxy-L-threonine (refs. 3-7 and Scheme 1). Astonishingly, although plants are a major source of vitamin B6 in the human diet, our understanding of the pathway therein is very limited and has been assumed to be derived the same way as in E. coli. There is one preliminary study that reports on its biosynthesis in spinach (8), whereas other, more in-depth studies have addressed the...

show abstract

Biosynthesis of 4‘-O-Methylpyridoxine (Ginkgotoxin) from Primary Precursors

Cited by 30 publications

References 16 publications

The Pdx1 family is structurally and functionally conserved between Arabidopsis thaliana and Ginkgo biloba

The Pdx1 family is structurally and functionally conserved between Arabidopsis thaliana and Ginkgo biloba

Genome Sequence of the Bacterium Streptomyces davawensis JCM 4913 and Heterologous Production of the Unique Antibiotic Roseoflavin

Vitamin B6 biosynthesis in higher plants

Contact Info

Product

Resources

About