title: ydaG and ydbA of Lactococcus lactis encode a heterodimeric ATP-binding cassette-type multidrug transporter.
abstract: Multidrug resistance (MDR)-type transporters mediate the active extrusion of structurally and functionally dissimilar compounds from the cells, thereby rendering cells resistant to a range of drugs. The ydaG and ydbA genes of Lactococcus lactis encode two ATP-binding cassette half-transporters, which both share homology with MDR proteins such as LmrA from L. lactis or the mammalian P-glycoprotein. The ydaG/ydbA genes were cloned and expressed separately and jointly in L. lactis using the nisin-inducible system. When both proteins are co-expressed, several structurally dissimilar drugs such as ethidium, daunomycin, and BCECF-AM are extruded from the cell. YdaG and YdbA could be co-purified as a stable heterodimer. ATPase activity was found to be associated with the YdaG/YdbA heterodimer only and not with the individual subunits. Both the ydaG and ydbA genes are up-regulated in multidrug-resistant L. lactis strains selected for growth in the presence of a variety of toxic compounds. This is the first demonstration of a functional heterodimeric ATP-binding cassette-type MDR transporter.
authors.affiliation: Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Kerklaan 30, NL-9751 NN Haren, The Netherlands.
authors.forename: Jacek
authors.initials: J
authors.lastname: Lubelski
authors.forename: Piotr
authors.initials: P
authors.lastname: Mazurkiewicz
authors.forename: Ronald
authors.initials: R
authors.lastname: van Merkerk
authors.forename: Wil N
authors.initials: WN
authors.lastname: Konings
authors.forename: Arnold J M
authors.initials: AJ
authors.lastname: Driessen
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000502:physiology; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D004247:DNA / Q000737:chemistry; D003630:Daunorubicin / Q000494:pharmacology; D019281:Dimerization; D018432:Drug Resistance, Multiple; D004591:Electrophoresis, Polyacrylamide Gel; D004996:Ethidium / Q000494:pharmacology; D005452:Fluoresceins / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000494:pharmacology; D013294:Lactococcus lactis / Q000235:genetics* / Q000378:metabolism*; D011485:Protein Binding; D012313:RNA / Q000378:metabolism; D013997:Time Factors; D015854:Up-Regulation
chemical_list: D018528:ATP-Binding Cassette Transporters; D000903:Antibiotics, Antineoplastic; D005452:Fluoresceins; D005456:Fluorescent Dyes; C057433:2',7'-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein acetoxymethyl ester; D012313:RNA; D000255:Adenosine Triphosphate; D004247:DNA; D000251:Adenosine Triphosphatases; D004996:Ethidium; D003630:Daunorubicin