Molecular Playground/OmpG: Difference between revisions
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==Structural Features of OmpG== | ==Structural Features of OmpG== | ||
OmpG is a 14-stranded beta-barrel and in contrast to most porins, appears to function as a monomer.[1] The central pore of OmpG is wider than other E. coli porins and it is speculated that it may form a non-specific channel for the passive transport of larger oligosaccharides.[1] OmpG adopts two conformations: open and closed. At neutral pH the porin displays an open conformation. However at a more acidic pH the closed conformation is adopted. This closed conformation is a result of OmpG's flexible extracellular loop 6, which folds across the channel blocking the pore opening. The rearrangement of loop 6 appears to be triggered by a pair of histidine residues, which repel | OmpG is a 14-stranded beta-barrel and in contrast to most porins, appears to function as a monomer.[1] The central pore of OmpG is wider than other E. coli porins and it is speculated that it may form a non-specific channel for the passive transport of larger oligosaccharides.[1] OmpG adopts two conformations: open and closed. At neutral pH the porin displays an open conformation. However at a more acidic pH the closed conformation is adopted. This closed conformation is a result of OmpG's flexible extracellular loop 6, which folds across the channel blocking the pore opening. The rearrangement of loop 6 appears to be triggered by a pair of histidine residues, which repel each another at acidic pH, resulting in the breakage of neighbouring H-bonds and a lengthening of loop 6 from 10 to 17 residues[2,3]. <scene name='User:Christina_Chisholm/Sandbox_1/Greenwoselection_ompg/3'></scene> | ||
[[Image:OmpG Conformation.png|thumb|]] | [[Image:OmpG Conformation.png|thumb|]] | ||
[2IWW] | [2IWW] | ||
[http://en.wikipedia.org/wiki/Outer_membrane_protein_G]. | [http://en.wikipedia.org/wiki/Outer_membrane_protein_G]. | ||
The loop environment of OmpG carries a net negative charge. This highly negative character may be implicated in the gating behavior of OmpG. If we can gain a deeper understanding of OmpG gating, we could could use this knowledge to tune it for specific detection of target analytes. | |||
==Current OmpG Projects in the Chen Lab== | |||
Engineering loop 6 to detect large protein analytes | |||
Investigating the effect of loop charge on the gating behavior of OmpG | |||
==Additional Resources== | ==Additional Resources== | ||