title: Activation of the Escherichia coli cell division protein FtsZ by a low-affinity interaction with monovalent cations.
abstract: We have investigated the activation of FtsZ by monovalent cations. FtsZ polymerization was dependent on the concentrations of protein and monovalent salts, and was accompanied by the uptake of a single ion per monomer added. The affinity and the specificity for the cation were low. Potassium, ammonium, rubidium or sodium activated FtsZ to different extents. Electron microscopy showed that polymers formed with either rubidium, or potassium, were very similar, as were their nucleotide turnover rates. The GTPase activity was lower with rubidium than with potassium, indicating that nucleotide exchange is independent of nucleotide hydrolysis. Control of polymerization by binding of a low affinity cation might govern the dynamic behavior of the FtsZ polymers.
authors.affiliation: Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
authors.forename: Michael
authors.initials: M
authors.lastname: Tadros
authors.forename: José Manuel
authors.initials: JM
authors.lastname: González
authors.forename: Germán
authors.initials: G
authors.lastname: Rivas
authors.forename: Miguel
authors.initials: M
authors.lastname: Vicente
authors.forename: Jesús
authors.initials: J
authors.lastname: Mingorance
mesh_terms: D002414:Cations, Monovalent / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D006160:Guanosine Triphosphate / Q000737:chemistry / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D020836:Protein Structure, Quaternary; D011868:Radioisotopes / Q000737:chemistry / Q000378:metabolism; D012413:Rubidium / Q000378:metabolism
chemical_list: D002414:Cations, Monovalent; D029968:Escherichia coli Proteins; C076835:FtsZ84 protein, E coli; D011868:Radioisotopes; D006160:Guanosine Triphosphate; D012413:Rubidium; D011188:Potassium