Abstract Background The C-3′,4′-dideoxygenation structure in gentamicin can prevent deactivation by aminoglycoside 3′-phosphotransferase (APH(3′)) drug-resistant pathogens. However, the enzyme catalyzing dideoxygenation step biosynthesis pathway remains unknown. Results Here, we report that GenP catalyzes 3′ phosphorylation of intermediates JI-20A, JI-20Ba, and JI-20B. We further demonstrate py...

Pure 2-amino-3-ketobutyrate CoA ligase from Escherichia coli, which catalyzes the cleavage/condensation reaction between 2-amino-3-ketobutyrate (the presumed product of the L-threonine dehydrogenase-catalyzed reaction) and glycine + acetyl-CoA, is a dimeric enzyme (Mr = 84,000) that requires pyridoxal 5'-phosphate as coenzyme for catalytic activity. Reduction of the hololigase with tritiated Na...

We describe the electroencephalographic and clinical seizure manifestations of pyridoxal 5'-phosphate-dependent epilepsy (PLP-DE) in two patients [diagnosis confirmed by low cerebrospinal fluid (CSF) PLP, complete resolution of previously intractable seizures with PLP supplementation, negative pyridoxine-dependent epilepsy CSF biomarkers, and/or positive disease causing pyridox(am)ine 5'-phosph...

The predominant biosynthetic route to vitamin B6 is catalyzed by a single enzyme. The synthase subunit of this enzyme, Pdx1, operates in concert with the glutaminase subunit, Pdx2, to catalyze the complex condensation of ribose 5-phosphate, glutamine and glyceraldehyde 3-phosphate to form pyridoxal 5¢-phosphate, the active form of vitamin B6. In previous studies it became clear that many if not...

nM. Thus, pyridloxal-P is the principal B6 vitaimer in plasma. Durinig pyridoxine stupplemiienitation, mealn plasnma levels of the B6 vitaimers anid pyridoxic acidl increasedl to 655±122 aindl 222±55 nM, respectively. The plasma content of pyridoxal-P aind( pyricloxic acidl increased 6-7-fold anid thatt of pyridoxal, 12-fold, but the pyridloxiine level did niot increase. Isolatedlhepatocytes, 1...

Pyridoxal-PO* binds to pepsinogen in a reaction in which the stoichiometry is highly dependent on the conformation of the protein. When pepsinogen is in its native conformation, pyridoxal-PO4 forms Schiff bases with the (r-NH2 group of Leul and the e-NH2 group of LysZS8. When the protein is mildly denatured and assumes a more extended conformation, pyridoxal-PO4 can react with the t-NH2 groups ...