Disease relevance of pdxB

• Divergent transcription of pdxB and homology between the pdxB and serA gene products in Escherichia coli K-12 [1].
• However, D-2-hydroxyisocaproate dehydrogenase from Lactobacillus casei, glycerate dehydrogenase from cucumber, D-3-phosphoglycerate dehydrogenase and erythronate 4-phosphate dehydrogenase from Escherichia coli showed 38%, 24%, 24% and 22% amino acid identity, respectively [2].
• Overexpression, crystallization and preliminary X-ray crystallographic analysis of erythronate-4-phosphate dehydrogenase from Pseudomonas aeruginosa [3].

High impact information on pdxB

• Here, we report cloning of a gene designated pdxR that functionally corresponds to the pdxB gene of E. coli and encodes a dye-linked flavin adenine dinucleotide-dependent 4-phospho-D-erythronate (4PE) dehydrogenase [4].
• Positive growth rate-dependent regulation of the pdxA, ksgA, and pdxB genes of Escherichia coli K-12 [5].
• Significantly, the requirement of the pdxB pdxK pdxY triple mutant for PLP was not satisfied by PL and PN, and the triple mutant had negligible PL and PN kinase specific activities [6].
• The SerA enzyme is evolutionarily related to the pdxB gene product, 4-phosphoerythronate dehydrogenase, which catalyzes the second step in one branch of pyridoxal 5'-phosphate coenzyme biosynthesis [7].
• Growth responses of pdxA, pdxB, and serC mutants to beta-hydroxypyruvate, D-alanine, and glycolate could also be reconciled with the proposed pathway [8].

Chemical compound and disease context of pdxB

• Pyridoxine-requiring mutants of Escherichia coli: glycolaldehyde dehydrogenase is not coded for by the pdxB gene [9].
• The NADH-dependent hydroxypyruvate reductase from cucumber and the pdxB gene product of E. coli display significant homology to E. coli D-3-phosphoglycerate dehydrogenase [10].

Biological context of pdxB

• Thus, pdxB must be the first gene in the complex pdxB-hisT operon [1].
• The DNA sequence confirms results from previous minicell experiments showing that pdxB encodes a 41-kilodalton polypeptide [1].
• We show that the minimum size of the operon is approximately 3,500 base pairs and that it contains at least four genes, which are arranged in the order usg-2 (pdxB), usg-1, hisT, and dsg-1 and encode polypeptides with apparent molecular masses of 42,000, 45,000, 31,000, and 17,000 daltons, respectively [11].
• Complementation experiments confirmed that usg-2 is indeed pdxB, and inspection of the pyridoxine biosynthetic pathway suggests explanations for the unusual phenotypes of pdxB::Kmr mutants [12].

Associations of pdxB with chemical compounds

• We report the DNA sequence and in vivo transcription start of pdxB, which encodes a protein required for de novo biosynthesis of pyridoxine (vitamin B6) [1].
• Furthermore, the fact that 4-hydroxythreonine, a probable intermediate in pyridoxine biosynthesis, is structurally related to serine strongly suggests that the pdxB gene product is erythronate-4-phosphate dehydrogenase [1].

References