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| Subject Categories: Cell Cycle | Microbiology & Pathogens |
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| The EMBO Journal
(2007) 26, 4694–4708, doi:10.1038/sj.emboj.7601895 Published online 18 October 2007 |
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| The structure of FtsZ filaments in vivo suggests a force-generating role in cell division |
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| Zhuo Li1, Michael J Trimble2, Yves V Brun2 and Grant J Jensen1 |
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1 Division of Biology, California Institute of Technology, Pasadena, CA, USA 2 Department of Biology, Indiana University, Bloomington, IN, USA To whom correspondence should be addressed Grant J Jensen, Division of Biology, California Institute of Technology, 1200 East California Blvd., MC: 114-96, Pasadena, CA 91125, USA. Tel.: +1 626 395 8827; Fax: +1 626 395 5730; E-mail: jensen@caltech.edu Received 25 May 2007; Accepted 26 September 2007; Published online 18 October 2007. |
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| Abstract |
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In prokaryotes, FtsZ (the filamentous temperature sensitive protein Z) is a nearly ubiquitous GTPase that localizes in a ring at the leading edge of constricting plasma membranes during cell division. Here we report electron cryotomographic reconstructions of dividing Caulobacter crescentus cells wherein individual arc-like filaments were resolved just underneath the inner membrane at constriction sites. The filaments' position, orientation, time of appearance, and resistance to A22 all suggested that they were FtsZ. Predictable changes in the number, length, and distribution of filaments in cells where the expression levels and stability of FtsZ were altered supported that conclusion. In contrast to the thick, closed-ring-like structure suggested by fluorescence light microscopy, throughout the constriction process the Z-ring was seen here to consist of just a few short ( 100 nm) filaments spaced erratically near the division site. Additional densities connecting filaments to the cell wall, occasional straight segments, and abrupt kinks were also seen. An 'iterative pinching' model is proposed wherein FtsZ itself generates the force that constricts the membrane in a GTP-hydrolysis-driven cycle of polymerization, membrane attachment, conformational change, depolymerization, and nucleotide exchange. |
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| Keywords: bacterial cytoskeleton, cell division, cryoelectron microscopy, FtsZ, tomography |
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Top of page MORE ARTICLES LIKE THISThese links to content published by NPG are automatically generated NEWS AND VIEWSNature Structural & Molecular Biology News and Views (01 Aug 2006) Structural biology Synchronized division proteins Nature News and Views (08 Jan 1998) RESEARCHTubulin-like protofilaments in Ca 2+ -induced FtsZ sheets The EMBO Journal Article (04 May 1999) |
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