Porin: Difference between revisions

One representative porin structure is the crystal structure osmoporin OmpC from ''Escherichia coli'' ([[2j1n]]). OmpC has three beta-barrels associated to form a <scene name='Porin/Cv/2'>tight trimer</scene> <ref>PMID:16949612</ref>. Porin is a transmembrane protein, as can be seen from the <jmol><jmolLink><script>script "/scripts/1a0s/Hidrophobic/1.spt"; ppdiaCaptionCmd = "changeCaption('Hydrophobic residues (shown in tan) are prevalent where the protein comes in contact with the hydrophbic layer of the double-layer membrane, while other parts of the surface are hydrophilic (hydrophilic residues, ordered water molecules and calcium ions shown in skyblue). Shown here is the sucrose-specific porin (PDB-ID 1a0s) in its trimeric quaternary structure.','white','black');";javascript @ppdiaCaptionCmd;</script><text>hydrophobic ring</text></jmolLink></jmol> around the protein, this makes it possible to submerge in the lipid bilayer (hydrophobic amino acids are sandybrown, hydrophilic ones are cyan). As you can <scene name='1a0s/Hidrophobic1/1'>see</scene> the channel in the protein is made of mainly hydrophilic chains thus making it possible for the sugar to pass through (these scenes were created by Nádori Gergely). The channels have wide openings on either side with a tighter bottleneck in the middle, as illustrated in the interaction view <scene name='41/411405/Channels/2'>visualizing channels</scene> with pseudoatoms, as well as in the animation below (view perpendicular to the membrane, slicing through different layers of the porin structure with the solvent accessible surface shown in tan).