The Cell Division Protein FtsZ from Streptococcus pneumoniae Exhibits a GTPase Activity Delay

J Biol Chem. 2015 Oct 9;290(41):25081-9. doi: 10.1074/jbc.M115.650077. Epub 2015 Sep 1.


The cell division protein FtsZ assembles in vitro by a mechanism of cooperative association dependent on GTP, monovalent cations, and Mg(2+). We have analyzed the GTPase activity and assembly dynamics of Streptococcus pneumoniae FtsZ (SpnFtsZ). 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 Mg(2+) 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.

Keywords: GTPase; Streptococcus; bacterial division; protein assembly; protein chemistry; protein dynamic.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism*
  • Cytoskeletal Proteins / chemistry
  • Cytoskeletal Proteins / metabolism*
  • GTP Phosphohydrolases / metabolism*
  • Guanosine Diphosphate / metabolism
  • Kinetics
  • Protein Multimerization
  • Protein Structure, Quaternary
  • Streptococcus pneumoniae*


  • Bacterial Proteins
  • Cytoskeletal Proteins
  • FtsZ protein, Bacteria
  • Guanosine Diphosphate
  • GTP Phosphohydrolases