title: The ether-cleaving methyltransferase of the strict anaerobe Acetobacterium dehalogenans: analysis of the zinc-binding site.
abstract: The anaerobic phenyl methyl ether cleavage in acetogenic bacteria is mediated by multicomponent enzyme systems designated O-demethylases. Depending on the growth substrate, different O-demethylases are induced in Acetobacterium dehalogenans. A vanillate- and a veratrol-O-demethylase of this organism have been described earlier. The methyltransferase I (MT I), a component of this enzyme system, catalyzes the ether cleavage and the transfer of the methyl group to a super-reduced corrinoid bound to a protein. The MT I of the vanillate- and veratrol-O-demethylase (MT I(van) and MT I(ver)) were found to be zinc-containing enzymes. By site-directed mutagenesis, putative zinc ligands were identified, from which the following unique zinc-binding motifs were derived: E-X(14)-E-X(20)-H for MT I(van) and D-X(27)-C-X(39)-C for MT I(ver).
authors.affiliation: Institut für Mikrobiologie, Lehrstuhl für Angewandte und Ökologische Mikrobiologie, Friedrich-Schiller-Universität Jena, Jena, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Studenik
authors.forename: Sandra
authors.initials: S
authors.lastname: Kreher
authors.forename: Gabriele
authors.initials: G
authors.lastname: Diekert
mesh_terms: D045855:Acetobacterium / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D004986:Ether / Q000378:metabolism*; D008780:Methyltransferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D015032:Zinc / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004986:Ether; D008780:Methyltransferases; D015032:Zinc