Biosynthesis of vitamins B 1 and B 6 in Escherichia coli : concurrent incorporation of 1-deoxy- D -xylulose into thiamin (B 1 ) and pyridoxol (B 6 )

It is shown by 13C NMR spectroscopy that, in Escherichia coli mutant WG2, the C-2,-3 bond of [2,3-13C2]-1-deoxy-D-xylulose 2 enters C-4,-5 of the thiazole unit of thiamin (B1) 1 and C-2,-3 of pyridoxol (B6) 3, providing the first direct evidence that the intact C5 chain of 1-deoxy-D-xylulose is incorporated concurrently into each of the two B Vitamins.