The Cell Division Protein FtsZ from Streptococcus pneumoniae Exhibits a GTPase Activity Delay.
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.
From the Servicio de Microbiología, Hospital Universitario La Paz, IdiPAZ, 28046 Madrid, Spain, Biomol-Informatics S.L., Universidad Autónoma, 28049 Madrid, Spain, esalvarelli@gmail.com.
Estefanía
E
Salvarelli
the Centro Nacional de Biotecnología and.
Marcin
M
Krupka
the Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, 28040 Madrid, Spain.
Germán
G
Rivas
From the Servicio de Microbiología, Hospital Universitario La Paz, IdiPAZ, 28046 Madrid, Spain.
Jesus
J
Mingorance
Biomol-Informatics S.L., Universidad Autónoma, 28049 Madrid, Spain, the Molecular Modelling Group, Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain, and.
Paulino
P
Gómez-Puertas
the Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, 28040 Madrid, Spain.
Carlos
C
Alfonso
the Centro Nacional de Biotecnología and.
Ana Isabel
AI
Rico
D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000378:metabolism*; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D006153:Guanosine Diphosphate / Q000378:metabolism; D007700:Kinetics; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D013296:Streptococcus pneumoniae
D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; C071525:FtsZ protein, Bacteria; D006153:Guanosine Diphosphate; D020558:GTP Phosphohydrolases
GTPase; Streptococcus; bacterial division; protein assembly; protein chemistry; protein dynamic