Molecular characterization of methanogenic N(5)-methyl-tetrahydromethanopterin : coenzyme M methyltransferase

  • Methanogenic archaea share one ion gradient forming reaction in their energy metabolism catalyzed by the membrane-spanning multisubunit complex N5-methyl-tetrahydromethanopterin: coenzyme M methyltransferase (MtrABCDEFGH or simply Mtr). In this reaction the methyl group transfer from methyl-tetrahydromethanopterin to coenzyme M mediated by cobalamin is coupled with the vectorial translocation of Na+ across the cytoplasmic membrane. No detailed structural and mechanistic data are reported about this process. In the present work we describe a procedure to provide a highly pure and homogenous Mtr complex on the basis of a selective removal of the only soluble subunit MtrH with the membrane perturbing agent dimethyl maleic anhydride and a subsequent two-step chromatographic purification. A molecular mass determination of the Mtr complex by laser induced liquid bead ion desorption mass spectrometry (LILBID-MS) and size exclusion chromatography coupled with multi-angle light scattering (SEC-MALS) resulted in a (MtrABCDEFG)3 heterotrimeric complex of ca. 430 kDa with both techniques. Taking into account that the membrane protein complex contains various firmly bound small molecules, predominantly detergent molecules, the stoichiometry of the subunits is most likely 1:1. A schematic model for the subunit arrangement within the MtrABCDEFG protomer was deduced from the mass of Mtr subcomplexes obtained by harsh IR-laser LILBID-MS.

Download full text files

  • 1-s2.0-S000527361630219X-main.pdf
  • 1-s2.0-S000527361630219X-mmc1.pdf
  • 1-s2.0-S000527361630219X-mmc2.docx

Export metadata

Author:Vikrant Upadhyay, Katharina Ceh, Franz Tumulka, Rupert Abele, Jan Hoffmann, Julian David Langer, Seigo Shima, Ulrich Ermler
Pubmed Id:
Parent Title (English):Biochimica et biophysica acta
Place of publication:Amsterdam
Document Type:Article
Year of Completion:2016
Date of first Publication:2016/06/21
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2018/01/09
Tag:Dimethyl maleic anhydride; LILBID-MS; Membrane protein complex; Methanogenesis; N5 -methyl-tetrahydromethanopterin: coenzyme M methyltransferase; SEC-MALS
Page Number:5
First Page:2140
Last Page:2144
Under an Elsevier user license
Institutes:Biochemie, Chemie und Pharmazie / Biochemie und Chemie
Angeschlossene und kooperierende Institutionen / MPI für Biophysik
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie
Licence (German):License LogoArchivex. zur Lesesaalplatznutzung § 52b UrhG