title: The role of the MxaD protein in the respiratory chain of Methylobacterium extorquens during growth on methanol.
abstract: The largest of the gene clusters coding for proteins involved in methanol oxidation is the cluster mxaFJGIR(S)ACKLDEHB. Disruption of most of these genes leads to lack of growth on methanol. The previous results showed that the mutant lacking MxaD grows on methanol although at a low rate. This is explained by the low rate of methanol oxidation by whole cells. The specific activity of methanol dehydrogenase (MDH) is higher in the mutant but its electron acceptor (cytochrome c(L)) is unchanged. Using the purified proteins, it was shown that the rate of interaction of MDH and cytochrome c(L) was higher in the wild-type MDH containing some MxaD proteins, which was absent in the mutant MDH. It is suggested that the gene mxaD codes for the 17-kDa periplasmic protein that directly or indirectly stimulates the interaction between MDH and cytochrome c(L); its absence leads to a lower rate of respiration with methanol and therefore a lower growth rate on this substrate.
authors.affiliation: Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753-8515, Japan. toyama@agr.yamaguchi-u.ac.jp
authors.forename: Hirohide
authors.initials: H
authors.lastname: Toyama
authors.forename: Hideko
authors.initials: H
authors.lastname: Inagaki
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Matsushita
authors.forename: Christopher
authors.initials: C
authors.lastname: Anthony
authors.forename: Osao
authors.initials: O
authors.lastname: Adachi
mesh_terms: D000429:Alcohol Oxidoreductases / Q000502:physiology*; D001426:Bacterial Proteins / Q000502:physiology*; D003574:Cytochrome c Group; D004579:Electron Transport; D000432:Methanol / Q000378:metabolism*; D020601:Methylobacterium extorquens / Q000378:metabolism*; D005810:Multigene Family; D010084:Oxidation-Reduction; D045542:PQQ Cofactor; D015363:Quinolones / Q000378:metabolism; D011809:Quinones / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D003574:Cytochrome c Group; D015363:Quinolones; D011809:Quinones; D045542:PQQ Cofactor; C058498:cytochrome C(L); D000429:Alcohol Oxidoreductases; C019641:alcohol dehydrogenase (acceptor); D000432:Methanol