Independence between GTPase active sites in the Escherichia coli cell division protein FtsZ

AbstractWe have analyzed the substrate kinetics of the GTPase activity of FtsZ and the effects of two different GTPase inhibitors, GDP and the slowly hydrolyzable GTP analogue GMPCPP. In the absence of inhibitors the GTPase activity follows simple Michaelis–Menten kinetics, and both GDP and GMPCPP inhibited the activity in a competitive manner. These results indicate that the GTPase active sites in FtsZ filaments are independent of each other, a feature relevant to elucidate the role of GTP hydrolysis in FtsZ function and cell division.Structured summary of protein interactionsFtsZ and FtsZ bind by light scattering (View interaction)

The cell division protein FtsZ from Streptococcus pneumoniae exhibits a GTPase activity delay

© 2015 by The American Society for Biochemistry and Molecular Biology, Inc.. The cell division protein FtsZ assembles in vitro by a mechanism of cooperative association dependent on GTP, monovalent cations, and Mg2+. We have analyzed the GTPase activity and assembly dynamics of Streptococcus pneumoniae FtsZ (Spn-FtsZ). SpnFtsZ assembled in an apparently cooperative process, with a higher critical concentration than values reported for other FtsZ proteins. It sedimented in the presence of GTP as a high molecular mass polymer with a well defined size and tended to form double-stranded filaments in electron microscope preparations. GTPase activity depended on K+ and Mg2+ and was inhibited by Na+. GTP hydrolysis exhibited a delay that included a lag phase followed by a GTP hydrolysis activation step, until reaction reached the GTPase rate. The lag phase was not found in polymer assembly, suggesting a transition from an initial non-GTP-hydrolyzing polymer that switches to a GTP-hydrolyzing polymer, supporting models that explain FtsZ polymer cooperativity.Spanish Government GrantsBIO2011-28941-C03 (to G. R. and C. A.) and BIO2011-28941-C01; Torres Quevedo Program Grant PTQ-11-05049 to Biomol Informatics S.L.Peer Reviewe

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LYON1-BU Santé (693882101) / SudocSudocFranceF

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LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

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LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

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LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

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LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF