The Outer Membrane Protein OmpW Forms an Eight-stranded β-Barrel with a Hydrophobic Channel

• Published in: The Journal of biological chemistry 2006-03, Vol.281 (11), p.7568
• Main Authors: Heedeok Hong, Dimki R. Patel, Lukas K. Tamm, Bert van den Berg
• Format: Article
• Language: English
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M512365200

Escherichia coli OmpW belongs to a family of small outer membrane proteins that are widespread in Gram-negative bacteria. Their functions are unknown, but recent data suggest that they may be involved in the protection of bacteria against various forms of environmental stress. To gain insight into the function of these proteins Å we have determined the crystal structure of E. coli OmpW to 2.7-A resolution. The structure shows that OmpW forms an 8-stranded β-barrel with a long and narrow hydrophobic channel that contains a bound n -dodecyl- N , N -dimethylamine- N -oxide detergent molecule. Single channel conductance experiments show that OmpW functions as an ion channel in planar lipid bilayers. The channel activity can be blocked by the addition of n -dodecyl- N , N -dimethylamine- N -oxide. Taken together, the data suggest that members of the OmpW family could be involved in the transport of small hydrophobic molecules across the bacterial outer membrane.