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Title: Crystal Structure of the Monomeric Porin OmpG

Abstract

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 Angstroms. The structure shows a 14-stranded {beta}{beta}-barrel with a relatively simple architecture. Due to the absence of loops that fold back into the channel, OmpG has a large ({approx}13 Angstroms) central pore that is considerably wider than those of other E. coli porins, and very similar in size to that of the toxin a-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 pointmore » for engineering studies aiming to generate selective channels and for the development of biosensors.« less

Authors:
;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
914037
Report Number(s):
BNL-78605-2007-JA
Journal ID: ISSN 0022-2836; JMOBAK; TRN: US0801492
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: J. Mol. Biol.; Journal Volume: 360; Journal Issue: 4
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 43 PARTICLE ACCELERATORS; BACTERIA; CRYSTAL STRUCTURE; ESCHERICHIA COLI; MEMBRANES; MONOMERS; NUTRIENTS; OLIGOSACCHARIDES; PORINS; PROTEINS; RESOLUTION; TOXINS; TRANSPORT; NSLS; national synchrotron light source

Citation Formats

Subbarao,G., and van den Berg, B. Crystal Structure of the Monomeric Porin OmpG. United States: N. p., 2006. Web. doi:10.1016/j.jmb.2006.05.045.
Subbarao,G., & van den Berg, B. Crystal Structure of the Monomeric Porin OmpG. United States. doi:10.1016/j.jmb.2006.05.045.
Subbarao,G., and van den Berg, B. Sun . "Crystal Structure of the Monomeric Porin OmpG". United States. doi:10.1016/j.jmb.2006.05.045.
@article{osti_914037,
title = {Crystal Structure of the Monomeric Porin OmpG},
author = {Subbarao,G. and van den Berg, B.},
abstractNote = {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 Angstroms. The structure shows a 14-stranded {beta}{beta}-barrel with a relatively simple architecture. Due to the absence of loops that fold back into the channel, OmpG has a large ({approx}13 Angstroms) central pore that is considerably wider than those of other E. coli porins, and very similar in size to that of the toxin a-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.},
doi = {10.1016/j.jmb.2006.05.045},
journal = {J. Mol. Biol.},
number = 4,
volume = 360,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}
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