K. Umezawa et al., Biosynthesis of polyoxypeptin A: novel amino acid 3-hydroxy-3-methylproline derived from isoleucine, J CHEM S P1, (13), 2001, pp. 1550-1553
Polyoxypeptin A is a hexadepsipeptide, isolated from Streptomyces, containi
ng the novel amino acid (2S,3R)-3-hydroxy-3-methylproline. Its biosynthetic
pathway is studied by incorporation of stable isotope-labelled amino acids
and carboxylic acids. (2S,3R)-3-Hydroxy-3-methylproline is shown to be der
ived from isoleucine but not from proline. Isoleucine is also incorporated
into the alkyl moiety of the C-15 acyl side chain, possibly through alpha -
methylbutyryl-CoA. The piperazic acid moieties are synthesized from glutama
te. Other hydroxylated amino acids are shown to be derived from each corres
ponding amino acid.