Mechanism of the asymmetric activation of the MinD ATPase by MinE.
MinD is a component of the Min system involved in the spatial regulation of cell division. It is an ATPase in the MinD/ParA/Mrp deviant Walker A motif family which is within the P loop GTPase superfamily. Its ATPase activity is stimulated by MinE; however, the mechanism of this activation is unclear. MinD forms a symmetric dimer with two binding sites for MinE; however, a recent model suggested that MinE occupying one site was sufficient for ATP hydrolysis. By generating heterodimers with one binding site for MinE we show that one binding site is sufficient for stimulation of the MinD ATPase. Furthermore, comparison of structures of MinD and related proteins led us to examine the role of N45 in the switch I region. An asparagine at this position is conserved in four of the deviant Walker A motif subfamilies (MinD, chromosomal ParAs, Get3 and FleN) and we find that N45 in MinD is essential for MinE-stimulated ATPase activity and suggest that it is a key residue affected by MinE binding.
Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS 66160, USA.
Kyung-Tae
KT
Park
Wei
W
Wu
Scott
S
Lovell
Joe
J
Lutkenhaus
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D001665:Binding Sites; D018797:Cell Cycle Proteins / Q000378:metabolism*; D017124:Conserved Sequence; D019281:Dimerization; D004926:Escherichia coli / Q000201:enzymology* / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D006868:Hydrolysis; D008954:Models, Biological; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation
D018797:Cell Cycle Proteins; D029968:Escherichia coli Proteins; C093548:MinE protein, E coli; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; C072069:MinD protein, E coli