NMR Polypeptide Backbone Conformation of the E.*coli Outer Membrane Protein W

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NMR Polypeptide Backbone Conformation of the E.*coli Outer Membrane Protein W

Publication date: Available online 10 July 2014
Source:Structure

Author(s): Reto Horst , Pawel Stanczak , Kurt Wüthrich

The outer membrane proteins (Omps) are key factors for bacterial survival and virulence. Among the Omps that have been structurally characterized either by X-ray crystallography or by NMR in solution, the crystal structure of OmpW stands out because three of its four extracellular loops are well defined, whereas long extracellular loops in other E.*coli Omps are disordered in the crystals as well as in NMR structures. OmpW thus presented an opportunity for a detailed comparison of the extracellular loops in a ?-barrel membrane protein structure in crystals and in noncrystalline milieus. Here, the polypeptide backbone conformation of OmpW in 30-Fos micelles was determined. Complete backbone NMR assignments were obtained and the loops were structurally characterized. In combination with the OmpW crystal structure, NMR line shape analyses, and 15N{1H}-NOE data, these results showed that intact regular secondary structures in the loops undergo slow hinge motions at the detergent-solvent interface.

Teaser

Horst et*al. determined the structure and dynamics of the E.*coli outer membrane protein W (OmpW) solubilized in 30-Fos micelles. Combined with previous crystal structures, these results show that secondary structures formed by the extracellular loops undergo slow hinge motions at the detergent-solvent interface.





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