This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Addinall, S. G. Articles by Khattar, M. M. Search for Related Content PubMed PubMed Citation Articles by Addinall, S. G. Articles by Khattar, M. M.

 Previous Article  |  Next Article 

Journal of Bacteriology, January 2005, p. 358-365, Vol. 187, No. 1
0021-9193/05/$08.00+0     doi:10.1128/JB.187.1.358-365.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

New Temperature-Sensitive Alleles of ftsZ in Escherichia coli

Stephen G. Addinall,¹ Elaine Small,¹ Duncan Whitaker,² Shane Sturrock,² William D. Donachie,² and Medhat M. Khattar^3*

School of Biological Sciences, University of Manchester, Manchester, United Kingdom,¹ Institute of Cell and Molecular Biology, University of Edinburgh, Edinburgh, Scotland,² Department of Biology, American University of Beirut, Beirut, Lebanon³

Received 2 June 2004/ Accepted 17 September 2004

We isolated five new temperature-sensitive alleles of the essential cell division gene ftsZ in Escherichia coli, using P1-mediated, localized mutagenesis. The five resulting single amino acid changes (Gly₁₀₉Ser₁₀₉ for ftsZ6460, Ala₁₂₉Thr₁₂₉ for ftsZ972, Val₁₅₇Met₁₅₇ for ftsZ2066, Pro₂₀₃Leu₂₀₃ for ftsZ9124, and Ala₂₃₉Val₂₃₉ for ftsZ2863) are distributed throughout the FtsZ core region, and all confer a lethal cell division block at the nonpermissive temperature of 42°C. In each case the division block is associated with loss of Z-ring formation such that fewer than 2% of cells show Z rings at 42°C. The ftsZ9124 and ftsZ6460 mutations are of particular interest since both result in abnormal Z-ring formation at 30°C and therefore cause significant defects in FtsZ polymerization, even at the permissive temperature. Neither purified FtsZ9124 nor purified FtsZ6460 exhibited polymerization when it was assayed by light scattering or electron microscopy, even in the presence of calcium or DEAE-dextran. Hence, both mutations also cause defects in FtsZ polymerization in vitro. Interestingly, FtsZ9124 has detectable GTPase activity, although the activity is significantly reduced compared to that of the wild-type FtsZ protein. We demonstrate here that unlike expression of ftsZ84, multicopy expression of the ftsZ6460, ftsZ972, and ftsZ9124 alleles does not complement the respective lethalities at the nonpermissive temperature. In addition, all five new mutant FtsZ proteins are stable at 42°C. Therefore, the novel isolates carrying single ftsZ(Ts) point mutations, which are the only such strains obtained since isolation of the classical ftsZ84 mutation, offer significant opportunities for further genetic characterization of FtsZ and its role in cell division.

---

* Corresponding author. Mailing address: Department of Biology, American University of Beirut, Beirut, Lebanon. Phone: 961 1 350000, ext. 3909 or 3923. Fax: 961 1 744461. E-mail: medhat{at}aub.edu.lb.

---

Journal of Bacteriology, January 2005, p. 358-365, Vol. 187, No. 1
0021-9193/05/$08.00+0     doi:10.1128/JB.187.1.358-365.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

This article has been cited by other articles:

• Yoder, D. W., Kadirjan-Kalbach, D., Olson, B. J. S. C., Miyagishima, S.-y., DeBlasio, S. L., Hangarter, R. P., Osteryoung, K. W. (2007). Effects of Mutations in Arabidopsis FtsZ1 on Plastid Division, FtsZ Ring Formation and Positioning, and FtsZ Filament Morphology in Vivo. Plant Cell Physiol 48: 775-791 [Abstract] [Full Text]  
• Michie, K. A., Monahan, L. G., Beech, P. L., Harry, E. J. (2006). Trapping of a Spiral-Like Intermediate of the Bacterial Cytokinetic Protein FtsZ.. J. Bacteriol. 188: 1680-1690 [Abstract] [Full Text]