This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Lu, W. P. Articles by Ragsdale, S. W. Search for Related Content PubMed PubMed Citation Articles by Lu, W. P. Articles by Ragsdale, S. W.

Next Article 

J. Bacteriol., May 1995, 2245-2250, Vol 177, No. 9
Copyright © 1995, American Society for Microbiology

Electron paramagnetic resonance spectroscopic and electrochemical characterization of the partially purified N5- methyltetrahydromethanopterin:coenzyme M methyltransferase from Methanosarcina mazei Go1

WP Lu, B Becher, G Gottschalk and SW Ragsdale
Department of Biochemistry, University of Nebraska, Lincoln 68583-0718, USA.

The N5-methyltetrahydromethanopterin:coenzyme M methyltransferase is a membrane-bound cobalamin-containing protein of Methanosarcina mazei Go1 that couples the methylation of coenzyme M by methyltetra- hydrosarcinopterin to the translocation of Na+ across the cell membrane (B. Becher, V. Muller, and G. Gottschalk, J. Bacteriol. 174:7656-7660, 1992). We have partially purified this enzyme and shown that, in addition to the cobamide, at least one iron-sulfur cluster is essential for the transmethylation reaction. The membrane fraction or the partly purified protein contains a "base-on" cobamide with a standard reduction potential (Eo') for the Co2+/1+ couple of -426 mV. The iron- sulfur cluster appears to be a [4Fe-4S]2+/1+ type with an Eo' value of - 215 mV. We have determined the methyltransferase activity at various controlled redox potentials and demonstrated that the enzyme activity is activated by a one-electron reduction with half-maximum activity occurring at -235 mV in the presence of ATP and -450 mV in its absence. No activation was observed when ATP was replaced by other nucleoside triphosphates or nonhydrolyzable ATP analogs.

This article has been cited by other articles:

• Schafer, G., Engelhard, M., Muller, V. (1999). Bioenergetics of the Archaea. Microbiol. Mol. Biol. Rev. 63: 570-620 [Abstract] [Full Text]  
• Burke, S. A., Krzycki, J. A. (1997). Reconstitution of Monomethylamine:Coenzyme M Methyl Transfer with a Corrinoid Protein and Two Methyltransferases Purified from Methanosarcina barkeri. J. Biol. Chem. 272: 16570-16577 [Abstract] [Full Text]  
• Daas, P. J.H., Hagen, W. R., Keltjens, J. T., van der Drift, C., Vogels, G. D. (1996). Activation Mechanism of Methanol:5-Hydroxybenzimidazolylcobamide Methyltransferase from Methanosarcina barkeri. J. Biol. Chem. 271: 22346-22351 [Abstract] [Full Text]