title: Mode of Interaction of the Signal-Transducing Protein EIIA(Glc) with the Maltose ABC Transporter in the Process of Inducer Exclusion.
abstract: Enzyme IIA(Glc) (EIIA(Glc)) of the phosphoenolpyruvate phosphotransferase system for the uptake of glucose in Escherichia coli and Salmonella inhibits the maltose ATP-binding cassette transporter (MalE-FGK2) by interaction with the nucleotide-binding and -hydrolyzing subunit MalK, a process termed inducer exclusion. We have investigated binding of EIIA(Glc) to the MalK dimer by cysteine cross-linking in proteoliposomes. The results prove that the binding site I of EIIA(Glc) is contacting the N-terminal subdomain of MalK while the binding site II is relatively close to the C-terminal (regulatory) subdomain, in agreement with a crystal structure [ Chen , S. , Oldham , M. L. , Davidson , A. L. , and Chen , J. ( 2013 ) Nature 499 , 364 - 368 ]. Moreover, EIIA(Glc) was found to bind to the MalK dimer regardless of its conformational state. Deletion of the amphipathic N-terminal peptide of EIIA(Glc), which is required for inhibition, reduced formation of cross-linked products. Using a spin-labeled transporter variant and EPR spectroscopy, we demonstrate that EIIA(Glc) arrests the transport cycle by inhibiting the ATP-dependent closure of the MalK dimer.
authors: Institut für Biologie, AG Bakterienphysiologie, Humboldt-Universität zu Berlin , Unter den Linden 6, 10099 Berlin, Germany.
authors: Steven
authors: S
authors: Wuttge
authors: Institut für Biologie, AG Bakterienphysiologie, Humboldt-Universität zu Berlin , Unter den Linden 6, 10099 Berlin, Germany.
authors: Anke
authors: A
authors: Licht
authors: Fachbereich Physik, Freie Universität Berlin , Arnimallee 14, 14195 Berlin, Germany.
authors: M Hadi
authors: MH
authors: Timachi
authors: Fachbereich Physik, Freie Universität Berlin , Arnimallee 14, 14195 Berlin, Germany.
authors: Enrica
authors: E
authors: Bordignon
authors: Institut für Biologie, AG Bakterienphysiologie, Humboldt-Universität zu Berlin , Unter den Linden 6, 10099 Berlin, Germany.
authors: Erwin
authors: E
authors: Schneider
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D019281:Dimerization; D029968:Escherichia coli Proteins / Q000378:metabolism*; D008320:Maltose / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding
chemical_list: D018528:ATP-Binding Cassette Transporters; D029968:Escherichia coli Proteins; D008320:Maltose