β-aminoglutaric acid is a major soluble component of Methanococcus thermolithotrophicus

• Published in: Biochimica et biophysica acta Vol. 992; no. 3; pp. 320 - 326
• Main Authors: Robertson, Diane E., Lesage, Suzanne, Roberts, Mary F.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.09.1989; Elsevier; North-Holland
• Subjects: 13C; 15N; Aminoacids, peptides. Hormones. Neuropeptides; Anaerobiosis; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Carbon Isotopes; Euryarchaeota - analysis; Euryarchaeota - growth & development; Fundamental and applied biological sciences. Psychology; Glutamates - biosynthesis; Glutamates - isolation & purification; Glutamates - metabolism; Lactates - metabolism; M. thermolithotrophicus; Magnetic Resonance Spectroscopy; Methanogenic bacterium; Nitrogen; NMR; Proteins; β-Aminoglutaric acid; β-Aminoglutaric acid; NMR; M. thermolithotrophicus; Methanogenic bacterium; Archaeobacteria; Microorganism culture; Bacteria; Biosynthesis; NMR spectrometry; Methanococcaceae; Methanococcales; Pulse labelling
• ISSN: 0304-4165; 0006-3002; 1872-8006; 1878-2434
• DOI: 10.1016/0304-4165(89)90091-3

13C- and 15N-NMR spectroscopy have been used to identify β-aminoglutaric acid (β-glutamic) as a major soluble component of the thermophilic, autotrophic marine methanogen Methanococcus thermolithotrophicus. This rare, non-protein amino acid has been recognized as a major dissolved free amino acid in marine sediments, but the microorganism responsible for its production has not previously been identified. The concentration of β-aminoglutarate (β-glutamate) is about one half that of free α-glutamate and increases (relative to the α-isomer) as cells enter the stationary phase. Analysis of the 13C label distribution in a 13CO 2-pulse/ 12CO 2-chase experiment shows that label enters the β-aminoglutarate pool after it has decayed from other small soluble molecules. This implies that β-aminoglutarate is a catabolic product of the cells. Preliminary biosynthesis studies with labeled precursors indicate that only a single acetate moiety is incorporated in this unusual compound. This information is used to suggest possible biosynthetic pathways.