Change search
ReferencesLink to record
Permanent link

Direct link
ATP-Induced Conformational Dynamics in the AAA plus Motor Unit of Magnesium Chelatase
KTH, School of Technology and Health (STH).
Show others and affiliations
2010 (English)In: Structure, ISSN 0969-2126, E-ISSN 1878-4186, Vol. 18, no 3, 354-365 p.Article in journal (Refereed) Published
Abstract [en]

Mg-chelatase catalyzes the first committed step of the chlorophyll biosynthetic pathway, the ATP-dependent insertion of Mg2+ into protoporphyrin IX (PPIX). Here we report the reconstruction using single-particle cryo-electron microscopy of the complex between subunits BchD and BchI of Rhodobacter capsulatus Mg-chelatase in the presence of ADP, the nonhydrolyzable ATP analog AMPPNP, and ATP at 7.5 angstrom, 14 angstrom, and 13 angstrom resolution, respectively. We show that the two AAA+ modules of the subunits form a unique complex of 3 dimers related by a three-fold axis. The reconstructions demonstrate substantial differences between the conformations of the complex in the presence of ATIP and ADP, and suggest that the C-terminal integrin-I domains of the BchD subunits play a central role in transmitting conformational changes of BchI to BchD. Based on these data a model for the function of magnesium chelatase is proposed.

Place, publisher, year, edition, pages
2010. Vol. 18, no 3, 354-365 p.
Keyword [en]
protoporphyrin ix chelatase, rhodobacter-sphaeroides, chlorophyll, biosynthesis, synechocystis pcc6803, electron-microscopy, barley, mutants, mg-chelatase, swiss-model, subunit-d, protein
National Category
Biochemistry and Molecular Biology
URN: urn:nbn:se:kth:diva-19306DOI: 10.1016/j.str.2010.01.001ISI: 000275492000012OAI: diva2:337353
QC 20110114Available from: 2010-08-05 Created: 2010-08-05 Last updated: 2012-03-21Bibliographically approved
In thesis
1. Towards unbiased 3D reconstruction: in single-particle cryo-electron microscopy
Open this publication in new window or tab >>Towards unbiased 3D reconstruction: in single-particle cryo-electron microscopy
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Cryo-electron microscopy of freestanding molecules (single-particles) plays a pivotal role in the difficult and pressing challenge of determining the structures of large macromolecular complexes. Molecular volumes are generated by aligning large sets of randomly oriented two-dimensional (2D) projection images in three dimensions (3D) before reconstruction is performed using tomographic techniques. The increasing popularity of the single-particle method is highly correlated with technical advances in instrumentation and computation. This thesis introduces new computational methods for 3D structure determination from electron microscopic projection images of single molecules. The algorithms have been developed to fill a gap in the single particle methodology – the lack of methods for ab initio 3D reconstruction of asymmetrical or low-symmetry molecules co-existing in different functional states. The proposed approach does not rely on a priori information about the structure or the character of the sample heterogeneity, which minimizes template dependence and makes the methods applicable to a wide range of single molecules. The presented algorithms constitute the basis of a new open source software package - SIMPLE (Single-particle IMage Processing Linux Engine). SIMPLE is an efficient and easy-to-use image processing system for semi-automated ab initio 3D reconstruction from challenging single-particle data sets (asymmetrical particles, significant degree of heterogeneity).

Place, publisher, year, edition, pages
Stockholm: KTH, 2010. 38 p.
Trita-STH : report, ISSN 1653-3836 ; 2010:7
National Category
Industrial Biotechnology
urn:nbn:se:kth:diva-27612 (URN)978-91-7415-837-3 (ISBN)
Public defence
2011-01-14, Föreläsningssalen, Novum, Hälsovägen 7, Huddinge, 10:00 (English)
QC 20101214Available from: 2010-12-14 Created: 2010-12-14 Last updated: 2010-12-16Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Elmlund, HansElmlund, DominikaHebert, HansLindahl, Martin
By organisation
School of Technology and Health (STH)Structural Biotechnology
In the same journal
Biochemistry and Molecular Biology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 92 hits
ReferencesLink to record
Permanent link

Direct link