Abstract
A fraction previously isolated from acid-treated supernatant fraction of Methanobacterium thermoautotrophicum by DEAE-Sephadex chromatography [Sauer, Mahadevan & Erfle (1984) Biochem. J. 221, 61-97] which was absolutely required for methane synthesis, has been separated into two compounds, tetrahydromethanopterin (H4MPT) and an as-yet-unidentified cofactor we call 'cytoplasmic cofactor'. H4MPT was identified by its u.v. spectrum and by 13C- and 1H-n.m.r. spectroscopy. The reduction of 2-(methylthio)ethanesulphonic acid (CH3-S-CoM) to methane by the membrane fraction from M. thermoautotrophicum was completely dependent on the addition of cytoplasmic cofactor. Methane synthesis from CO2, however, was only partially dependent on cofactor addition, and 57% of the original activity was retained in its absence. The kinetics of 14C labelling were consistent with the scheme methyl-H4MPT----CH3-S-CoM----methane, as has been proposed. This is the first time that direct experimental evidence has been presented to show that the proposed methyl transfer from H4MPT to coenzyme M (HS-CoM) actually occurs.
Full text
PDFSelected References
These references are in PubMed. This may not be the complete list of references from this article.
- Escalante-Semerena J. C., Leigh J. A., Rinehart K. L., Wolfe R. S. Formaldehyde activation factor, tetrahydromethanopterin, a coenzyme of methanogenesis. Proc Natl Acad Sci U S A. 1984 Apr;81(7):1976–1980. doi: 10.1073/pnas.81.7.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Escalante-Semerena J. C., Rinehart K. L., Jr, Wolfe R. S. Tetrahydromethanopterin, a carbon carrier in methanogenesis. J Biol Chem. 1984 Aug 10;259(15):9447–9455. [PubMed] [Google Scholar]
- Gonenne A., Ernst R. Solubilization of membrane proteins by sulfobetaines, novel zwitterionic surfactants. Anal Biochem. 1978 Jun 15;87(1):28–38. doi: 10.1016/0003-2697(78)90565-1. [DOI] [PubMed] [Google Scholar]
- Keltjens J. T., Daniels L., Jannsen H. G., Borm P. J., Vogels G. D. A novel one-carbon carrier (carboxy-5,6,7,8-tetrahydromethanopterin) isolated from Methanobacterium thermoautotrophicum and derived from methanopterin. Eur J Biochem. 1983 Feb 15;130(3):545–552. doi: 10.1111/j.1432-1033.1983.tb07184.x. [DOI] [PubMed] [Google Scholar]
- Keltjens J. T., Huberts M. J., Laarhoven W. H., Vogels G. D. Structural elements of methanopterin, a novel pterin present in Methanobacterium thermoautotrophicum. Eur J Biochem. 1983 Feb 15;130(3):537–544. doi: 10.1111/j.1432-1033.1983.tb07183.x. [DOI] [PubMed] [Google Scholar]
- Leigh J. A., Rinehart K. L., Jr, Wolfe R. S. Methanofuran (carbon dioxide reduction factor), a formyl carrier in methane production from carbon dioxide in Methanobacterium. Biochemistry. 1985 Feb 12;24(4):995–999. doi: 10.1021/bi00325a028. [DOI] [PubMed] [Google Scholar]
- Nagle D. P., Jr, Wolfe R. S. Component A of the methyl coenzyme M methylreductase system of Methanobacterium: resolution into four components. Proc Natl Acad Sci U S A. 1983 Apr;80(8):2151–2155. doi: 10.1073/pnas.80.8.2151. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Paukert J. L., Straus L. D., Rabinowitz J. C. Formyl-methyl-methylenetetrahydrofolate synthetase-(combined). An ovine protein with multiple catalytic activities. J Biol Chem. 1976 Aug 25;251(16):5104–5111. [PubMed] [Google Scholar]
- Sauer F. D., Bush R. S., Mahadevan S., Erfle J. D. Methane production by cell-free particulate fraction of rumen bacteria. Biochem Biophys Res Commun. 1977 Nov 7;79(1):124–132. doi: 10.1016/0006-291x(77)90069-9. [DOI] [PubMed] [Google Scholar]
- Sauer F. D., Erfle J. D., Mahadevan S. Methane production by the membranous fraction of Methanobacterium thermoautotrophicum. Biochem J. 1980 Jul 15;190(1):177–182. doi: 10.1042/bj1900177. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sauer F. D., Erfle J. D., Mahadevan S. Methane synthesis without the addition of adenosine triphosphate by cell membranes isolated from Methanobacterium ruminantium. Biochem J. 1979 Jan 15;178(1):165–172. doi: 10.1042/bj1780165. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sauer F. D., Mahadevan S., Erfle J. D. Methane synthesis by membrane vesicles and a cytoplasmic cofactor isolated from Methanobacterium thermoautotrophicum. Biochem J. 1984 Jul 1;221(1):61–69. doi: 10.1042/bj2210061. [DOI] [PMC free article] [PubMed] [Google Scholar]
- van Beelen P., Stassen A. P., Bosch J. W., Vogels G. D., Guijt W., Haasnoot C. A. Elucidation of the structure of methanopterin, a coenzyme from Methanobacterium thermoautotrophicum, using two-dimensional nuclear-magnetic-resonance techniques. Eur J Biochem. 1984 Feb 1;138(3):563–571. doi: 10.1111/j.1432-1033.1984.tb07951.x. [DOI] [PubMed] [Google Scholar]