Journalartikel

Jahr der Veröffentlichung: 1993

Seiten: 530-536

Zeitschrift: Archives of Microbiology

Bandnummer: 159

Heftnummer: 6

ISSN: 0302-8933

DOI Link: https://doi.org/10.1007/BF00249031

Verlag: Springer

Abstract: 
Methanosarcina barkeri was recently shown to contain two cytoplasmic isoenzymes of methylcobalamin: coenzyme M methyltransferase (methyltransferase 2). Isoenzyme I predominated in methanol-grown cells and isoenzyme II in acetate-grown cells. It was therefore suggested that isoenzyme I functions in methanogenesis from methanol and isoenzyme II in methanogenesis from acetate. We report here that cells of M. barkeri grown on trimethylamine, H-2/CO2, or acetate contain mainly isoenzyme II. These cells were found to have in common that they can catalyze the formation of methane from trimethylamine and H-2, whereas only acetate-grown cells can mediate the formation of methane from acetate. Methanol-grown cells, which contained only low concentrations of isoenzyme II, were unable to mediate the formation of methane from both trimethylamine and acetate. These and other results suggest that isoenzyme II (i) is employed for methane formation from trimethylamine rather than from acetate. (ii) is constitutively expressed rather than trimethylamine-induced, and (iii) is repressed by methanol. The constitutive expression of isoenzyme II in acetate-grown M. barkeri can explain its presence in these cells. The N-terminal amino acid sequences of isoenzyme I and isoenzyme II were analyzed and found to be only 55% similar.

Harvard-Zitierstil: YELISEEV, A., GARTNER, P., HARMS, U., LINDER, D. and THAUER, R. (1993) FUNCTION OF METHYLCOBALAMIN - COENZYME-M METHYLTRANSFERASE ISOENZYME-II IN METHANOSARCINA-BARKERI, Archives of Microbiology, 159(6), pp. 530-536. https://doi.org/10.1007/BF00249031

APA-Zitierstil: YELISEEV, A., GARTNER, P., HARMS, U., LINDER, D., & THAUER, R. (1993). FUNCTION OF METHYLCOBALAMIN - COENZYME-M METHYLTRANSFERASE ISOENZYME-II IN METHANOSARCINA-BARKERI. Archives of Microbiology. 159(6), 530-536. https://doi.org/10.1007/BF00249031