A complex of the Escherichia coli cell division proteins FtsL, FtsB and FtsQ forms independently of its localization to the septal region.
Three membrane proteins required for cell division in Escherichia coli, FtsQ, FtsL and FtsB, localize to the cell septum. FtsL and FtsB, which each contain a leucine zipper-like sequence, are dependent on each other for this localization, and each of them is dependent on FtsQ. However, FtsQ is found at the cell division site in the absence of FtsL and FtsB. FtsQ, in turn, requires FtsK for its localization. Here, we show that FtsL, FtsB and FtsQ form a complex in vivo. Strikingly, this complex forms in the absence of FtsK, which is required for the localization of all three proteins to the mid-cell. These findings indicate that the FtsL, FtsB, FtsQ interactions can take place in cells before movement to the mid-cell and that migration to this position might occur only after the formation of the complex. Evidence indicating the regions of the three proteins involved in complex formation is presented. These findings provide the first example of preassembly of a subcomplex of cell division proteins before their localization to the septal region.
Buddelmeijer
Nienke
N
Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA.
Beckwith
Jon
J
D018797:Cell Cycle Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division / Q000502:physiology*; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016350:Leucine Zippers; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary
D018797:Cell Cycle Proteins; D029968:Escherichia coli Proteins; C456028:FtsB protein, E coli; C096452:FtsK protein, E coli; C068023:FtsQ protein, E coli; D046911:Macromolecular Substances; D008565:Membrane Proteins; C078387:ftsL protein, E coli