S1.44 Mass determination of membrane protein complexes in detergent solution: The c rings from F-ATP synthases

Abstract Gaining knowledge of the structural makeup of protein complexes is critical to advance our understanding of their formation and functions. This task is particularly challenging for transmembrane protein complexes, and grows ever more imposing with increasing size of these large macromolecular structures. The last 10 years have seen a steep increase in solved high-resolution membrane protein structures due to both new and improved methods in the field, but still most structures of large transmembrane complexes remain elusive. An important first step towards the structure elucidation of these difficult complexes is the determination of their stoichiometry, which we discuss in this review. Knowing the stoichiometry of complex components not only answers unresolved structural questions and is relevant for understanding the molecular mechanisms of macromolecular machines but also supports further attempts to obtain high-resolution structures by providing constraints for structure calculations.

Download Full-text

Membrane protein megahertz crystallography at the European XFEL

Nature Communications ◽

10.1038/s41467-019-12955-3 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 11

Author(s):

Chris Gisriel ◽

Jesse Coe ◽

Romain Letrun ◽

Oleksandr M. Yefanov ◽

Cesar Luna-Chavez ◽

...

Keyword(s):

Data Collection ◽

Membrane Protein ◽

Protein Complexes ◽

Membrane Protein Complex ◽

Unit Cell Size ◽

Data Collection And Analysis ◽

Rapid Pulse ◽

Membrane Protein Complexes ◽

Increasing Demand

Abstract The world’s first superconducting megahertz repetition rate hard X-ray free-electron laser (XFEL), the European XFEL, began operation in 2017, featuring a unique pulse train structure with 886 ns between pulses. With its rapid pulse rate, the European XFEL may alleviate some of the increasing demand for XFEL beamtime, particularly for membrane protein serial femtosecond crystallography (SFX), leveraging orders-of-magnitude faster data collection. Here, we report the first membrane protein megahertz SFX experiment, where we determined a 2.9 Å-resolution SFX structure of the large membrane protein complex, Photosystem I, a > 1 MDa complex containing 36 protein subunits and 381 cofactors. We address challenges to megahertz SFX for membrane protein complexes, including growth of large quantities of crystals and the large molecular and unit cell size that influence data collection and analysis. The results imply that megahertz crystallography could have an important impact on structure determination of large protein complexes with XFELs.

Download Full-text

Conformational Flexibility in Assembly of Photosynthetic Membrane Protein Complexes in vivo

Microscopy and Microanalysis ◽

10.1017/s1431927604881534 ◽

2004 ◽

Vol 10 (S02) ◽

pp. 1496-1497

Author(s):

P A Bullough

Keyword(s):

Membrane Protein ◽

Protein Complexes ◽

Conformational Flexibility ◽

Photosynthetic Membrane ◽

Membrane Protein Complexes

Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.

Download Full-text

Three-dimensional crystallization of membrane proteins

Quarterly Reviews of Biophysics ◽

10.1017/s0033583500004625 ◽

1988 ◽

Vol 21 (4) ◽

pp. 429-477 ◽

Cited By ~ 156

Author(s):

W. Kühlbrandt

Keyword(s):

High Resolution ◽

Membrane Proteins ◽

Membrane Protein ◽

Protein Complexes ◽

Three Dimensional ◽

Biological Macromolecules ◽

X Ray ◽

X Ray Crystallography ◽

Membrane Protein Complexes ◽

Essential Prerequisite

As recently as 10 years ago, the prospect of solving the structure of any membrane protein by X-ray crystallography seemed remote. Since then, the threedimensional (3-D) structures of two membrane protein complexes, the bacterial photosynthetic reaction centres of Rhodopseudomonas viridis (Deisenhofer et al. 1984, 1985) and of Rhodobacter sphaeroides (Allen et al. 1986, 1987 a, 6; Chang et al. 1986) have been determined at high resolution. This astonishing progress would not have been possible without the pioneering work of Michel and Garavito who first succeeded in growing 3-D crystals of the membrane proteins bacteriorhodopsin (Michel & Oesterhelt, 1980) and matrix porin (Garavito & Rosenbusch, 1980). X-ray crystallography is still the only routine method for determining the 3-D structures of biological macromolecules at high resolution and well-ordered 3-D crystals of sufficient size are the essential prerequisite.

Download Full-text