title: Ribose biosynthesis and evidence for an alternative first step in the common aromatic amino acid pathway in Methanococcus maripaludis.
abstract: An acetate-requiring mutant of Methanococcus maripaludis allowed efficient labeling of riboses following growth in minimal medium supplemented with [2-(13)C]acetate. Nuclear magnetic resonance and mass spectroscopic analysis of purified cytidine and uridine demonstrated that the C-1' of the ribose was about 67% enriched for 13C. This value was inconsistent with the formation of erythrose 4-phosphate (E4P) exclusively by the carboxylation of a triose. Instead, these results suggest that either (i) E4P is formed by both the nonoxidative pentose phosphate and triose carboxylation pathways or (ii) E4P is formed exclusively by the nonoxidative pentose phosphate pathway and is not a precursor of aromatic amino acids.
authors.affiliation: Department of Microbiology, University of Georgia, Athens 30602-2605, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Tumbula
authors.forename: Q
authors.initials: Q
authors.lastname: Teng
authors.forename: M G
authors.initials: MG
authors.lastname: Bartlett
authors.forename: W B
authors.initials: WB
authors.lastname: Whitman
mesh_terms: D000085:Acetates / Q000378:metabolism; D000596:Amino Acids / Q000096:biosynthesis*; D003470:Culture Media; D003562:Cytidine / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D017017:Methanococcus / Q000378:metabolism*; D010427:Pentose Phosphate Pathway; D012266:Ribose / Q000096:biosynthesis*; D013403:Sugar Phosphates / Q000378:metabolism; D014529:Uridine / Q000378:metabolism
chemical_list: D000085:Acetates; D000596:Amino Acids; D003470:Culture Media; D013403:Sugar Phosphates; C026959:erythrose 4-phosphate; D003562:Cytidine; D012266:Ribose; D014529:Uridine