title: The salt-induced ABC transporter Ota of the methanogenic archaeon Methanosarcina mazei Gö1 is a glycine betaine transporter.
abstract: The genes encoding the three subunits of the primary ABC transporter Ota of the methanogenic archaeon Methanosarcina mazei Gö1 were cloned in an expression vector (pBAD24) and transformed into the glycine betaine transport-negative mutant Escherichia coli MKH13. Ota was produced as demonstrated by Western blotting. Uptake studies revealed that Ota catalyzed the transport of glycine betaine in E. coli MKH13(pBAD-Ota) with a K(m) of 10+/-5 microM and a maximal velocity of 1.5+/-0.5 nmol min(-1) mg protein(-1). Transport was ATP dependent. Ota was activated by salinity gradients, but only marginally by sugar gradients across the membrane. Glycine betaine transport was inhibited to a small extent by an excess of dimethylglycin or proline betaine, but not by sarcosine or glycine.
authors.affiliation: Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt, Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: Schmidt
authors.forename: Katharina
authors.initials: K
authors.lastname: Pflüger
authors.forename: Stephanie
authors.initials: S
authors.lastname: Kögl
authors.forename: Regina
authors.initials: R
authors.lastname: Spanheimer
authors.forename: Volker
authors.initials: V
authors.lastname: Müller
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism; D001622:Betaine / Q000378:metabolism; D003001:Cloning, Molecular; D003470:Culture Media; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D007700:Kinetics; D026901:Membrane Transport Proteins / Q000378:metabolism*; D017020:Methanosarcina / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*
chemical_list: D018528:ATP-Binding Cassette Transporters; D019843:Archaeal Proteins; D003470:Culture Media; D026901:Membrane Transport Proteins; D001622:Betaine; D012965:Sodium Chloride