2M06

NMR structure of OmpX in phopspholipid nanodiscs

Summary for 2M06

• Entry DOI: 10.2210/pdb2m06/pdb
• Related: 1q9f 1qj8 2M07
• NMR Information: BMRB: 18796
• Descriptor: Outer membrane protein X (1 entity in total)
• Functional Keywords: beta barrel, membrane protein, structural genomics, psi-biology, membrane protein structures by solution nmr, mpsbynmr
• Biological source: Escherichia coli
• Cellular location: Cell outer membrane; Multi-pass membrane protein: P0A917
• Total number of polymer chains: 1
• Total formula weight: 16395.81

Authors

Hagn, F.X.,Etzkorn, M.,Raschle, T.,Wagner, G.,Membrane Protein Structures by Solution NMR (MPSbyNMR) (deposition date: 2012-10-21, release date: 2012-12-12, Last modification date: 2024-05-15)

Primary citation

Hagn, F.,Etzkorn, M.,Raschle, T.,Wagner, G.
Optimized phospholipid bilayer nanodiscs facilitate high-resolution structure determination of membrane proteins.
J.Am.Chem.Soc., 135:1919-1925, 2013

PubMed Abstract: Structural studies of membrane proteins are still hampered by difficulties of finding appropriate membrane-mimicking media that maintain protein structure and function. Phospholipid nanodiscs seem promising to overcome the intrinsic problems of detergent-containing environments. While nanodiscs can offer a near-native environment, the large particle size complicates their routine use in the structural analysis of membrane proteins by solution NMR. Here, we introduce nanodiscs assembled from shorter ApoA-I protein variants that are of markedly smaller diameter and show that the resulting discs provide critical improvements for the structure determination of membrane proteins by NMR. Using the bacterial outer-membrane protein OmpX as an example, we demonstrate that the combination of small nanodisc size, high deuteration levels of protein and lipids, and the use of advanced non-uniform NMR sampling methods enable the NMR resonance assignment as well as the high-resolution structure determination of polytopic membrane proteins in a detergent-free, near-native lipid bilayer setting. By applying this method to bacteriorhodopsin, we show that our smaller nanodiscs can also be beneficial for the structural characterization of the important class of seven-transmembrane helical proteins. Our set of engineered nanodiscs of subsequently smaller diameters can be used to screen for optimal NMR spectral quality for small to medium-sized membrane proteins while still providing a functional environment. In addition to their key improvements for de novo structure determination, due to their smaller size these nanodiscs enable the investigation of interactions between membrane proteins and their (soluble) partner proteins, unbiased by the presence of detergents that might disrupt biologically relevant interactions.

PubMed: 23294159
DOI: 10.1021/ja310901f

Experimental method

SOLUTION NMR