Two independent routes of de novo vitamin B6 biosynthesis: not that different after all
| Autor: | Barbara Kappes, Peter Macheroux, Ivo Tews, Thomas Raschle, Nikolaus Amrhein, Thérésa Bridget Fitzpatrick |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Threonine
Vitamin Protein Conformation Nitrogenous Group Transferases Chemical Pentose phosphate pathway Biology Biochemistry Bacterial Proteins/chemistry/metabolism Fungal Proteins Ligases Structure-Activity Relationship chemistry.chemical_compound Bacterial Proteins Biosynthesis Models Glycolysis Threonine/analogs & derivatives/metabolism Fungal Proteins/chemistry/metabolism Molecular Biology Pyridoxal chemistry.chemical_classification Fungal protein Xylose Binding Sites Escherichia coli Proteins Vitamin B 6/biosynthesis Nitrogenous Group Transferases/chemistry/metabolism Organophosphates/metabolism Oxidoreductases/chemistry/metabolism Cell Biology Organophosphates Vitamin B 6 Xylose/analogs & derivatives/metabolism Enzyme Models Chemical chemistry Escherichia coli Proteins/chemistry/metabolism Ligases/chemistry/metabolism Oxidoreductases |
| Zdroj: | Biochemical Journal, Vol. 407, No 1 (2007) pp. 1-13 |
| ISSN: | 1470-8728 0264-6021 |
| DOI: | 10.1042/bj20070765 |
| Popis: | Vitamin B6 is well known in its biochemically active form as pyridoxal 5′-phosphate, an essential cofactor of numerous metabolic enzymes. The vitamin is also implicated in numerous human body functions ranging from modulation of hormone function to its recent discovery as a potent antioxidant. Its de novo biosynthesis occurs only in bacteria, fungi and plants, making it an essential nutrient in the human diet. Despite its paramount importance, its biosynthesis was predominantly investigated in Escherichia coli, where it is synthesized from the condensation of deoxyxylulose 5-phosphate and 4-phosphohydroxy-L-threonine catalysed by the concerted action of PdxA and PdxJ. However, it has now become clear that the majority of organisms capable of producing this vitamin do so via a different route, involving precursors from glycolysis and the pentose phosphate pathway. This alternative pathway is characterized by the presence of two genes, Pdx1 and Pdx2. Their discovery has sparked renewed interest in vitamin B6, and numerous studies have been conducted over the last few years to characterize the new biosynthesis pathway. Indeed, enormous progress has been made in defining the nature of the enzymes involved in both pathways, and important insights have been provided into their mechanisms of action. In the present review, we summarize the recent advances in our knowledge of the biosynthesis of this versatile molecule and compare the two independent routes to the biosynthesis of vitamin B6. Surprisingly, this comparison reveals that the key biosynthetic enzymes of both pathways are, in fact, very similar both structurally and mechanistically. |
| Databáze: | OpenAIRE |
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