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Low‐Resolution Structures of OmpA⋅DDM Protein–Detergent Complexes
Author(s) -
Døvling Kaspersen Jørn,
Moestrup Jessen Christian,
Stougaard Vad Brian,
Skipper Sørensen Esben,
Kleiner Andersen Kell,
Glasius Marianne,
Pinto Oliveira Cristiano Luis,
Otzen Daniel Erik,
Pedersen Jan Skov
Publication year - 2014
Publication title -
chembiochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 126
eISSN - 1439-7633
pISSN - 1439-4227
DOI - 10.1002/cbic.201402162
Subject(s) - periplasmic space , dimer , linker , monomer , transmembrane protein , small angle x ray scattering , chemistry , transmembrane domain , covalent bond , amphiphile , micelle , membrane protein , crystallography , biophysics , membrane , biochemistry , biology , escherichia coli , organic chemistry , aqueous solution , polymer , copolymer , receptor , physics , computer science , scattering , optics , gene , operating system
Abstract We have used SAXS to determine the low‐resolution structure of the outer‐membrane protein OmpA from E. coli solubilized by the surfactant dodecyl maltoside (DDM). We have studied three variants of the transmembrane domain of OmpA—namely monomers, self‐associated dimers, and covalently linked dimers—as well as the monomeric species of the full‐length protein with the periplasmic domain. We can successfully model the structures of the monomeric and covalently linked dimer as one and two natively folded proteins in a DDM micelle, respectively, whereas the noncovalently linked dimer presents a more complicated structure, possibly due to higher‐order species. We have determined the structure of the full‐length protein to be that of a globular periplasmic domain attached through a flexible linker to the transmembrane domain. This approach provides valuable information about how membrane proteins are embedded in amphiphilic environments.