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

J. Biol. Chem., Vol. 283, Issue 20, 14002-14011, May 16, 2008

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 283/20/14002    most recent M800625200v1 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 Qian, P. Articles by Hunter, C. N. Search for Related Content PubMed PubMed Citation Articles by Qian, P. Articles by Hunter, C. N. Social Bookmarking                      What's this?

Three-dimensional Reconstruction of a Membrane-bending Complex

THE RC-LH1-PufX CORE DIMER OF RHODOBACTER SPHAEROIDES^*

From the Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom

A three-dimensional model of the dimeric reaction center-light harvesting I-PufX (RC-LH1-PufX) complex from Rhodobacter sphaeroides, calculated from electron microscope single particle analysis of negatively stained complexes, shows that the two halves of the dimer molecule incline toward each other on the periplasmic side, creating a remarkable V-shaped structure. The distribution of negative stain is consistent with loose packing of the LH1 ring near the 14th LH1 /β pair, which could facilitate the migration of quinone and quinol molecules across the LH1 boundary. The three-dimensional model encloses a space near the reaction center Q_B site and the 14th LH1 /β pair, which is 20Å in diameter, sufficient to sequester a quinone pool. Helical arrays of dimers were used to construct a three-dimensional membrane model, which matches the packing lattice deduced from electron microscope analysis of the tubular dimer-only membranes found in mutants of Rba. sphaeroides lacking the LH2 complex. The intrinsic curvature of the dimer explains the shape and 70-nm diameter of these membrane tubules, and at least partially accounts for the spherical membrane invaginations found in wild-type Rba. sphaeroides. A model of dimer aggregation and membrane curvature in these spherical membrane invaginations is presented.

Received for publication, January 24, 2008 , and in revised form, March 5, 2008.

^* This work was supported by the Biotechnology and Biological Research Council, UK. 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.

The on-line version of this article (available at http://www.jbc.org) contains supplemental Figs. S1 and S2.

¹ To whom correspondence should be addressed. Tel.: 44-0-114-2224191; E-mail: c.n.hunter{at}sheffield.ac.uk.

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

This article has been cited by other articles:

				J. D. Olsen, J. D. Tucker, J. A. Timney, P. Qian, C. Vassilev, and C. N. Hunter The Organization of LH2 Complexes in Membranes from Rhodobacter sphaeroides J. Biol. Chem., November 7, 2008; 283(45): 30772 - 30779. [Abstract] [Full Text] [PDF]