title: Deletion analysis of gene minE which encodes the topological specificity factor of cell division in Escherichia coli.
abstract: Division inhibition caused by the minCD gene products of Escherichia coli is suppressed specifically at mid-cell by MinE protein expressed at physiological levels. Excess MinE allows division to take place also at the poles, leading to a minicell-forming (Min-) phenotype. In order to investigate the basis of this topological specificity, we have analysed the ability of truncated derivatives of MinE to suppress either minCD-dependent division inhibition in a chromosomal delta(minB) background, or the division inhibition exerted by MinCD at the cell poles in a minB+ strain. Our results indicate that these two effects are not mediated by identical interactions of MinE protein. In addition, gel filtration and the yeast two-hybrid system indicated that MinE interacts with itself by means of its central segment. Taken together, our results favour a model in which wild-type MinE dimer molecules direct the division inhibitor molecules to the cell poles, thus preventing polar divisions and allowing non-polar sites to divide. This model explains how excess MinE, or an excess of certain MinE derivatives which prevent the accumulation of the division inhibitor at the poles, can confer a Min- phenotype in a minB+ strain.
authors.affiliation: Laboratoire de Microbiologie, Génétique Moléculaire du CNRS, Toulouse, France.
authors.forename: S
authors.initials: S
authors.lastname: Pichoff
authors.forename: B
authors.initials: B
authors.lastname: Vollrath
authors.forename: C
authors.initials: C
authors.lastname: Touriol
authors.forename: J P
authors.initials: JP
authors.lastname: Bouché
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D018797:Cell Cycle Proteins; D002455:Cell Division / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D010641:Phenotype; D010957:Plasmids / Q000235:genetics; D017421:Sequence Analysis; D017384:Sequence Deletion; D013489:Suppression, Genetic
chemical_list: D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; D029968:Escherichia coli Proteins; C093548:MinE protein, E coli