title: Membrane localization of MinD is mediated by a C-terminal motif that is conserved across eubacteria, archaea, and chloroplasts.
abstract: MinD is a widely conserved ATPase that has been demonstrated to play a pivotal role in selection of the division site in eubacteria and chloroplasts. It is a member of the large ParA superfamily of ATPases that are characterized by a deviant Walker-type ATP-binding motif. MinD localizes to the cytoplasmic face of the inner membrane in Escherichia coli, and its association with the inner membrane is a prerequisite for membrane recruitment of the septation inhibitor MinC. However, the mechanism by which MinD associates with the membrane has proved enigmatic; it seems to lack a transmembrane domain and the amino acid sequence is devoid of hydrophobic tracts that might predispose the protein to interaction with lipids. In this study, we show that the extreme C-terminal region of MinD contains a highly conserved 8- to 12-residue sequence motif that is essential for membrane localization of the protein. We provide evidence that this motif forms an amphipathic helix that most likely mediates a direct interaction between MinD and membrane phospholipids. A model is proposed whereby the membrane-targeting motif mediates the rapid cycles of membrane attachment-release-reattachment that are presumed to occur during pole-to-pole oscillation of MinD in E. coli.
authors.affiliation: Department of Biochemistry, University of Connecticut Health Center, 263 Farmington Avenue, 06032, USA.
authors.forename: Tim H
authors.initials: TH
authors.lastname: Szeto
authors.forename: Susan L
authors.initials: SL
authors.lastname: Rowland
authors.forename: Lawrence I
authors.initials: LI
authors.lastname: Rothfield
authors.forename: Glenn F
authors.initials: GF
authors.lastname: King
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000235:genetics; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001105:Archaea / Q000201:enzymology*; D019843:Archaeal Proteins / Q000737:chemistry*; D001419:Bacteria / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry*; D002462:Cell Membrane / Q000201:enzymology*; D002736:Chloroplasts / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics; D019143:Evolution, Molecular; D008565:Membrane Proteins / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010940:Plant Proteins / Q000737:chemistry*; D017433:Protein Structure, Secondary; D021381:Protein Transport; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D010940:Plant Proteins; D000251:Adenosine Triphosphatases; C072069:MinD protein, E coli; C439050:MinD protein, Neisseria gonorrhoeae