title: ZipA binds to FtsZ with high affinity and enhances the stability of FtsZ protofilaments.
abstract: A bacterial membrane protein ZipA that tethers FtsZ to the membrane is known to promote FtsZ assembly. In this study, the binding of ZipA to FtsZ was monitored using fluorescence spectroscopy. ZipA was found to bind to FtsZ with high affinities at three different (6.0, 6.8 and 8.0) pHs, albeit the binding affinity decreased with increasing pH. Further, thick bundles of FtsZ protofilaments were observed in the presence of ZipA under the pH conditions used in this study indicating that ZipA can promote FtsZ assembly and stabilize FtsZ polymers under unfavorable conditions. Bis-ANS, a hydrophobic probe, decreased the interaction of FtsZ and ZipA indicating that the interaction between FtsZ and ZipA is hydrophobic in nature. ZipA prevented the dilution induced disassembly of FtsZ polymers suggesting that it stabilizes FtsZ protofilaments. Fluorescein isothiocyanate-labeled ZipA was found to be uniformly distributed along the length of the FtsZ protofilaments indicating that ZipA stabilizes FtsZ protofilaments by cross-linking them.
authors.affiliation: Wadhwani Research Center, Department of Biosciences & Bioengineering, Indian Institute of Technology Bombay, Mumbai, India.
authors.forename: Anuradha
authors.initials: A
authors.lastname: Kuchibhatla
authors.forename: Anusri
authors.initials: A
authors.lastname: Bhattacharya
authors.forename: Dulal
authors.initials: D
authors.lastname: Panda
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D016923:Cell Death; D002455:Cell Division; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D008027:Light; D008856:Microscopy, Fluorescence / Q000379:methods; D008954:Models, Biological; D011108:Polymers / Q000737:chemistry; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012542:Scattering, Radiation
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D029968:Escherichia coli Proteins; C071525:FtsZ protein, Bacteria; D011108:Polymers; D011994:Recombinant Proteins; C103795:ZipA protein, E coli