2f1c
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Crystal structure of the monomeric porin OmpG
OverviewOverview
The outer membrane (OM) of Gram-negative bacteria contains a large number, of channel proteins that mediate the uptake of ions and nutrients, necessary for growth and functioning of the cell. An important group of OM, channel proteins are the porins, which mediate the non-specific, diffusion-based passage of small (<600 Da) polar molecules. All porins of, Gram-negative bacteria that have been crystallized to date form stable, trimers, with each monomer composed of a 16-stranded beta-barrel with a, relatively narrow central pore. In contrast, the OmpG porin is unique, as, it appears to function as a monomer. We have determined the X-ray crystal, structure of OmpG from Escherichia coli to a resolution of 2.3 A. The, structure shows a 14-stranded beta-barrel with a relatively simple, architecture. Due to the absence of loops that fold back into the channel, OmpG has a large ( approximately 13 A) central pore that is considerably, wider than those of other E. coli porins, and very similar in size to that, of the toxin alpha-hemolysin. The architecture of the channel, together, with previous biochemical and other data, suggests that OmpG may form a, non-specific channel for the transport of larger oligosaccharides. The, structure of OmpG provides the starting point for engineering studies, aiming to generate selective channels and for the development of, biosensors.
About this StructureAbout this Structure
2F1C is a Single protein structure of sequence from Escherichia coli with C8E as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of the monomeric porin OmpG., Subbarao GV, van den Berg B, J Mol Biol. 2006 Jul 21;360(4):750-9. Epub 2006 Jun 2. PMID:16797588
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