HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 283, Issue 13, 8102-8109, March 28, 2008

This Article Full Text Full Text (PDF) All Versions of this Article: 283/13/8102    most recent M709163200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Chen, Y. Articles by Erickson, H. P. Search for Related Content PubMed PubMed Citation Articles by Chen, Y. Articles by Erickson, H. P. Social Bookmarking                      What's this?

In Vitro Assembly Studies of FtsZ/Tubulin-like Proteins (TubZ) from Bacillus Plasmids

EVIDENCE FOR A CAPPING MECHANISM^*

From the Department of Cell Biology, Duke University Medical Center, Durham, North Carolina 27710

Proteins with a weak sequence similarity to tubulin and FtsZ are expressed from large plasmids of Bacillus anthracis and Bacillus thuringiensis and are probably involved in plasmid segregation. Previously designated RepX and TubZ, we designate them here as TubZ-Ba and TubZ-Bt. We have expressed and purified the proteins for in vitro studies. TubZ-Ba and TubZ-Bt share only 21% amino acid identity, but they have remarkably similar biochemical properties. They both assemble into two-stranded filaments and larger bundles above a critical concentration, and they hydrolyze GTP at a very high rate, 20 GTP min^–1 TubZ^–1. Assembly is also supported by GTPS. A tiny amount of GTPS stabilizes polymers assembled in GTP and inhibits the GTPase by a mechanism involving cooperativity. The nucleotide in the polymers is almost 100% GDP, which is similar to microtubules but very different from the 20–30% GDP in FtsZ polymers. This suggests that the TubZ polymers have a capping mechanism that may be related to the GTP cap that produces dynamic instability of microtubules.

Received for publication, November 7, 2007 , and in revised form, January 9, 2008.

^* This work was supported by National Institutes of Health Grant GM66014. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

¹ To whom correspondence should be addressed. Tel.: 919-684-6385; Fax: 919-684-8090; E-mail: h.Erickson{at}cellbio.duke.edu.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				P. Akhtar, S. P. Anand, S. C. Watkins, and S. A. Khan The Tubulin-Like RepX Protein Encoded by the pXO1 Plasmid Forms Polymers In Vivo in Bacillus anthracis J. Bacteriol., April 15, 2009; 191(8): 2493 - 2500. [Abstract] [Full Text] [PDF]

				X. Hu, W. Fan, B. Han, H. Liu, D. Zheng, Q. Li, W. Dong, J. Yan, M. Gao, C. Berry, et al. Complete Genome Sequence of the Mosquitocidal Bacterium Bacillus sphaericus C3-41 and Comparison with Those of Closely Related Bacillus Species J. Bacteriol., April 15, 2008; 190(8): 2892 - 2902. [Abstract] [Full Text] [PDF]