title: Corrinoid activation by a RACE protein: studies on the interaction of the proteins involved.
abstract: The O-demethylases of anaerobes are corrinoid-dependent, ether-cleaving methyltransferase enzyme systems consisting of four components. The interaction of the O-demethylase components of the acetogenic bacterium Acetobacterium dehalogenans was studied by protein mobility on native PAGE, far-Western blot analysis and yeast two-hybrid screen. Using native PAGE and far-Western blot, the interaction of the activating enzyme (AE) with its substrate, the corrinoid protein (CP), could be observed. The interaction occurred with four different CPs of A. dehalogenans and a CP from Desulfitobacterium hafniense DCB-2, all involved in ether cleavage. In the corrinoid reduction assay, the AE reduced all CPs tested. This result indicates a broad substrate specificity of the AE of A. dehalogenans. In addition, an interaction of the A. dehalogenans CP of the vanillate-O-demethylase with the two methyltransferases of the same enzyme system was observed. The interaction of the ether-cleaving methyltransferase with the CP appeared to be significantly less pronounced than that reported for the homologous methanol and methylamine methyltransferase systems of methanogenic archaea.
authors.affiliation: Institut für Mikrobiologie, Friedrich-Schiller-Universität Jena, Lehrstuhl für Angewandte und Ökologische Mikrobiologie, Jena, Germany.
authors.forename: Hai Dang
authors.initials: HD
authors.lastname: Nguyen
authors.forename: Sandra
authors.initials: S
authors.lastname: Studenik
authors.forename: Gabriele
authors.initials: G
authors.lastname: Diekert
mesh_terms: D045855:Acetobacterium / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D045728:Corrinoids / Q000378:metabolism*; D004789:Enzyme Activation; D020536:Enzyme Activators / Q000378:metabolism*; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism*; D010090:Oxidoreductases, O-Demethylating / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D045728:Corrinoids; D020536:Enzyme Activators; D010090:Oxidoreductases, O-Demethylating; D008780:Methyltransferases
keywords: O-demethylase; activating enzyme; corrinoid protein; protein-protein interaction