title: The Na+ transport in gram-positive bacteria defect in the Mrp antiporter complex measured with 23Na nuclear magnetic resonance.
abstract: (23)Na nuclear magnetic resonance (NMR) has previously been used to monitor Na(+) translocation across membranes in gram-negative bacteria and in various other organelles and liposomes using a membrane-impermeable shift reagent to resolve the signals resulting from internal and external Na(+). In this work, the (23)Na NMR method was adapted for measurements of internal Na(+) concentration in the gram-positive bacterium Bacillus subtilis, with the aim of assessing the Na(+) translocation activity of the Mrp (multiple resistance and pH) antiporter complex, a member of the cation proton antiporter-3 (CPA-3) family. The sodium-sensitive growth phenotype observed in a B. subtilis strain with the gene encoding MrpA deleted could indeed be correlated to the inability of this strain to maintain a lower internal Na(+) concentration than an external one.
authors.affiliation: Department of Biochemistry and Structural Biology, Center for Molecular Protein Science, Lund University, 221 00 Lund, Sweden.
authors.forename: Kamil
authors.initials: K
authors.lastname: Górecki
authors.forename: Cecilia
authors.initials: C
authors.lastname: Hägerhäll
authors.forename: Torbjörn
authors.initials: T
authors.lastname: Drakenberg
mesh_terms: D001412:Bacillus subtilis / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D017136:Ion Transport; D007477:Ions / Q000737:chemistry / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D012964:Sodium / Q000737:chemistry / Q000378:metabolism*; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D007477:Ions; D017923:Sodium-Hydrogen Exchangers; D012964:Sodium
keywords: Bacillus subtilis; Cation proton antiporter-3 family; Membrane transport; Mrp antiporter; NMR; Sodium concentration