RT Journal Article SR Electronic(1) A1 Lowe, D. A. A1 Turner, J. M.YR 1970 T1 Origin of the d-l-Aminopropan-2-ol Fragment of Vitamin B12 JF Microbiology, VO 64 IS 1 SP 119 OP 122 DO https://doi.org/10.1099/00221287-64-1-119 PB Microbiology Society, SN 1465-2080, AB SUMMARY: i-Aminopropan-2-ol is a component of vitamin B12 (Cooley, Ellis & Petrow, 1950) possessing the dg-configuration (Wolf, Jones, Valiant & Folkers, 1950). X-Ray crystallography confirmed that the amino alcohol linked the substituted corrin and nucleotide-like ring systems (Hodgkin et al. 1956; Hodgkin, 1958). The metabolic origin of the nitrogen atom of d-i-aminopropan-2-ol in vitamin B12 was established using [15N]-l-threonine, added to the growth medium of Streptomyces griseus (Krasna, Rosenblum & Sprinson, 1957). It was suggested that the carbon skeleton of the aminopropanol moiety was also derived from threonine by decarboxylation, although this was not investigated. Direct decarboxylation of the amino acid has never been demonstrated, and neither the threonine nor threonine-O-phos-phate analogues of vitamin B12 serve as precursors of cobinamide in either Escherichia coli or Propionibacterium shermanii (Bernhauer & Wagner, 1961, 1962). The discovery of l-threonine dehydrogenase (Neuberger & Tait, 1960, 1962) and d-i-aminopropan-2-ol dehydrogenase activity (Turner, 1966; Dekker & Swain, 1968; Lowe & Turner, 1968) revived interest in the possibility that the free amino alcohol, formed from l-threonine via aminoacetone, served as a precursor. The roles of l-threonine and d-i-aminopropan-2-ol in vitamin B12 biosynthesis by a Streptomyces strain were therefore investigated using 14C-labelled compounds., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-64-1-119