Visualization of single Escherichia coli FtsZ filament dynamics with atomic force microscopy.
FtsZ, the prokaryotic homologue of tubulin, is an essential cell division protein. In the cell, it localizes at the center, forming a ring that constricts during division. In vitro, it binds and hydrolyzes GTP and polymerizes in a GTP-dependent manner. We have used atomic force microscopy to study the structure and dynamics of FtsZ polymer assembly on a mica surface under buffer solution. The polymers were highly dynamic and flexible, and they continuously rearranged over the surface. End-to-end joining of filaments and depolymerization from internal zones were observed, suggesting that fragmentation and reannealing may contribute significantly to the dynamics of FtsZ assembly. The shape evolution of the restructured polymers manifested a strong inherent tendency to curve. Polymers formed in the presence of non-hydrolyzable nucleotide analogues or in the presence of GDP and AlF(3) were structurally similar but showed a slower dynamic behavior. These results provide experimental evidence supporting the model of single-strand polymerization plus cyclization recently proposed to explain the hydrodynamic behavior of the polymers in solution.
Mingorance
Jesús
J
Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas and Instituto Nicolás Cabrera, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid 28049, Spain.
Tadros
Michael
M
Vicente
Miguel
M
González
José Manuel
JM
Rivas
Germán
G
Vélez
Marisela
M
D000327:Adsorption; D017607:Aluminum Compounds / Q000494:pharmacology; D000538:Aluminum Silicates; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004926:Escherichia coli / Q000737:chemistry*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000648:ultrastructure*; D005459:Fluorides / Q000494:pharmacology; D006153:Guanosine Diphosphate / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D018625:Microscopy, Atomic Force; D011108:Polymers / Q000737:chemistry; D012996:Solutions
D017607:Aluminum Compounds; D000538:Aluminum Silicates; D029968:Escherichia coli Proteins; C076835:FtsZ84 protein, E coli; D011108:Polymers; D012996:Solutions; D006153:Guanosine Diphosphate; C004805:5'-guanylylmethylenebisphosphonate; D006160:Guanosine Triphosphate; D005459:Fluorides; C011934:mica; C032311:aluminum fluoride