title: Nucleotide sequence of the mxcQ and mxcE genes, required for methanol dehydrogenase synthesis in Methylobacterium organophilum XX: a two-component regulatory system.
abstract: Nucleotide sequence analysis of the mxcQ and mxcE loci, required for the synthesis of methanol dehydrogenase in Methylobacterium organophilum XX, has revealed two open reading frames that show significant similarity to sequences of prokaryotic two-component systems, especially MxaY and MxaX proteins of another methylotrophic bacterium, Paracoccus denitrificans. Cell-free extracts and DNA-column-fractionated proteins from wild-type M. organophilum XX cells grown on methanol or succinate contained protein(s) that were able to bind specifically to the upstream region of methanol dehydrogenase large subunit gene (mxaF). In contrast, cell-free extracts from mxcQ and mxcE mutant strains of M. organophilum XX had zero or reduced binding activity towards the promoter fragments of the mxaF gene. This is consistent with the involvement of the mxcQ and mxcE genes in transcriptional regulation of methanol dehydrogenase synthesis. Analyses of sequential deletions of the mxaF upstream region have defined the functional boundary of the promoter/operator region of this gene and identified one nucleotide segment as essential to the activation of mxaF.
authors.affiliation: Department of Microbiology, Gray Freshwater Biological Institute, University of Minnesota, Navarre 55392, USA.
authors.forename: H H
authors.initials: HH
authors.lastname: Xu
authors.forename: J J
authors.initials: JJ
authors.lastname: Janka
authors.forename: M
authors.initials: M
authors.lastname: Viebahn
authors.forename: R S
authors.initials: RS
authors.lastname: Hanson
mesh_terms: D000429:Alcohol Oxidoreductases / Q000096:biosynthesis* / Q000235:genetics; D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D001483:Base Sequence; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D005798:Genes, Bacterial; D006088:Gram-Negative Aerobic Bacteria / Q000201:enzymology / Q000235:genetics*; D000071677:Histidine Kinase; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011494:Protein Kinases / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C096672:MxcE protein, Methylobacterium organophilum; D000429:Alcohol Oxidoreductases; C019641:alcohol dehydrogenase (acceptor); D011494:Protein Kinases; D000071677:Histidine Kinase