title: Functional impact of a single mutation within the transmembrane domain of the multidrug ABC transporter Pdr5.
abstract: The pleiotropic drug resistance network in budding yeast presents a first line of defense against xenobiotics, which is formed by primary and secondary active membrane transporters. Among these transporters, the ABC transporter Pdr5 is a key component, because it confers resistance against a broad spectrum of such cytotoxic agents. Furthermore, it represents a model system for homologous transporters from pathogenic fungi and has been intensively studied in the past. In addition to other mutational studies, the S1360F mutation of Pdr5 was found to modulate substrate specificity and resistance. Notably, in the S1360F background, the resistance against the immunosuppressant FK506 is drastically increased. We present a detailed analysis of this mutation that is located in the predicted cytosolic part of transmembrane helix 11. Our data demonstrate that kinetic and thermodynamic parameters of the S1360F mutant are similar to those of the wild-type protein, except for FK506-inhibited ATPase activity and the degree of competitive inhibition. In summary, our results indicate that the S1360F mutation within the transmembrane domain interferes drastically with the ability of the nucleotide-binding domains to hydrolyze ATP by interfering with interdomain crosstalk.
authors: Institute of Biochemistry, Heinrich Heine University Duesseldorf, Universitaetsstrasse 1, 40225 Duesseldorf, Germany.
authors: Petra
authors: P
authors: Kueppers
authors: Rakeshkumar P
authors: RP
authors: Gupta
authors: Jan
authors: J
authors: Stindt
authors: Sander H J
authors: SH
authors: Smits
authors: Lutz
authors: L
authors: Schmitt
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000595:Amino Acid Sequence; D001692:Biological Transport; D005456:Fluorescent Dyes / Q000493:pharmacokinetics / Q000494:pharmacology; D006868:Hydrolysis; D007166:Immunosuppressive Agents / Q000493:pharmacokinetics / Q000494:pharmacology; D008969:Molecular Sequence Data; D017354:Point Mutation; D017434:Protein Structure, Tertiary; D012235:Rhodamines / Q000493:pharmacokinetics / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D013379:Substrate Specificity; D016559:Tacrolimus / Q000493:pharmacokinetics / Q000494:pharmacology
chemical_list: D018528:ATP-Binding Cassette Transporters; D005456:Fluorescent Dyes; D007166:Immunosuppressive Agents; C092438:PDR5 protein, S cerevisiae; D012235:Rhodamines; D029701:Saccharomyces cerevisiae Proteins; C026188:rhodamine 6G; D000255:Adenosine Triphosphate; D016559:Tacrolimus