MinC/MinD copolymers are not required for Min function.
In Escherichia coli, precise placement of the cytokinetic Z ring at midcell requires the concerted action of the three Min proteins. MinD activates MinC, an inhibitor of FtsZ, at least in part, by recruiting it to the membrane and targeting it to the Z ring, while MinE stimulates the MinD ATPase inducing an oscillation that directs MinC/MinD activity away from midcell. Recently, MinC and MinD were shown to form copolymers of alternating dimers of MinC and MinD, and it was suggested that these copolymers are the active form of MinC/MinD. Here, we use MinD mutants defective in binding MinC to generate heterodimers with wild-type MinD that are unable to form MinC/MinD copolymers. Similarly, MinC mutants defective in binding to MinD were used to generate heterodimers with wild-type MinC that are unable to form copolymers. Such heterodimers are active and in the case of MinC were shown to mediate spatial regulation of the Z ring demonstrating that MinC/MinD copolymer formation is not required. Our results are consistent with a model in which a membrane anchored MinC/MinD complex is targeted to the Z ring through the conserved carboxy tail of FtsZ leading to breakage of FtsZ filaments.
Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.
Kyung-Tae
KT
Park
Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.
Shishen
S
Du
Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.
Joe
J
Lutkenhaus
D000251:Adenosine Triphosphatases / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D055503:Protein Multimerization
D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; D029968:Escherichia coli Proteins; C071525:FtsZ protein, Bacteria; D008565:Membrane Proteins; C080466:MinC protein, Bacteria; D000251:Adenosine Triphosphatases