title: Biosynthesis of the polyoxins, nucleoside peptide antibiotics: glutamate as an origin of 2-amino-2-deoxy-L-xylonic acid (polyoxamic acid).
abstract: The biosynthetic origin of the carbon skeleton of 2-amino-2-deoxy-L-xylonic acid (polyoxamic acid) is described. This aminoaldonic acid is the N terminus of the nucleoside peptide antibiotics, the polyoxins, produced by Streptomyces cacaoi var. asoensis. In vivo experiments concerning incorporation and distribution of radioactivity from a number of 14C-labeled compounds have clearly shown that the carbon skeleton of glutamate is a precursor for this aminoaldonic acid and sugars are incorporated only after their conversion into gluamate through the glycolytic and the tricarboxylic acid cycle pathways. Experiments utilizing [14C]-acetate and succinate have also indicated multiple passages through the Krebs cycle are operating before their incorporation into polyoxamic acid via glutamate. The distribution of 14C between C-1 and C-5 of polyoxamic acid from [5-14C]glutamate experiment has indicated that 40% of glutamate incorporated only after the reversible conversion into alpha-ketoglutarate followed by the passage through the Krebs cycle. Lack of incorporation of 3H in the [1-14C;2-3H]- and [5-14C;2-3H]glutamate experiments is discussed in terms of a reaction(s) between glutamate and polyoxamic acid.
mesh_terms: D000085:Acetates / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D005947:Glucose / Q000378:metabolism; D005971:Glutamates / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D009705:Nucleosides / Q000378:metabolism*; D010072:Oxamic Acid; D010452:Peptide Biosynthesis; D011773:Pyruvates / Q000378:metabolism; D012266:Ribose / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D013302:Streptomyces / Q000378:metabolism*; D013386:Succinates / Q000378:metabolism; D013400:Sugar Acids / Q000378:metabolism
chemical_list: D000085:Acetates; D000596:Amino Acids; D000900:Anti-Bacterial Agents; D005971:Glutamates; D009705:Nucleosides; D011773:Pyruvates; D013386:Succinates; D013400:Sugar Acids; C529752:polyoxamic acid; D012694:Serine; D012266:Ribose; D005947:Glucose; D005990:Glycerol; D010072:Oxamic Acid