Porin: Difference between revisions
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<StructureSection load='' size='350' side='right' scene='Porin/Cv/1' caption='E. coli OmpC (PDB code [[2j1n]])'> | <StructureSection load='' size='350' side='right' scene='Porin/Cv/1' caption='E. coli OmpC is a trimeric transmembrane protein with a porin fold (PDB code [[2j1n]])'> | ||
__TOC__ | __TOC__ | ||
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*[[Molecular Playground/OmpG2]]<br /> | *[[Molecular Playground/OmpG2]]<br /> | ||
*[[Osmoporin OmpK36 (K. pneumoniae)]]<br /> | *[[Osmoporin OmpK36 (K. pneumoniae)]]<br /> | ||
'''Voltage-Dependent Anion Channel (VDAC)''' is ion channel Omp found in outer mitochondrial membrane. In Pseudomonas aeruginosa the porin gene products are named OprD, OprK, OprP. | '''Voltage-Dependent Anion Channel (VDAC)''' is ion channel Omp found in outer mitochondrial membrane. In Pseudomonas aeruginosa the porin gene products are named OprD, OprK, OprP. | ||
== Structure == | |||
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 off-white) are prevalent where the protein comes in contact with the hydrophbic layer of the double 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 hole 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). | |||
== 3D structures of Porin == | == 3D structures of Porin == | ||
Revision as of 19:24, 5 August 2023
FunctionPorin or Outer Membrane Proteins (Omps) act as channels which allow passive diffusion of sugars, ions and amino acids. They are beta barrel proteins which traverse the cell membrane. In E. coli they are named according to their genes: C, F, G, etc. (OmpC, OmpF, OmpG). Voltage-Dependent Anion Channel (VDAC) are ion channel Omps found in outer mitochondrial membrane[1]. In Pseudomonas aeruginosa the porin gene products are named OprD, OprE, OprK, OprP, etc. and OpdC, OpdH, etc. Maltoporin (LamB) facilitates the diffusion of maltodextrin across the membrane[2]. See more details in
Voltage-Dependent Anion Channel (VDAC) is ion channel Omp found in outer mitochondrial membrane. In Pseudomonas aeruginosa the porin gene products are named OprD, OprK, OprP.
StructureOne representative porin structure is the crystal structure osmoporin OmpC from Escherichia coli (2j1n). OmpC has three beta-barrels associated to form a [3]. Porin is a transmembrane protein, as can be seen from the 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 the hole 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). 3D structures of Porin
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ReferencesReferences
- ↑ Shoshan-Barmatz V, Israelson A, Brdiczka D, Sheu SS. The voltage-dependent anion channel (VDAC): function in intracellular signalling, cell life and cell death. Curr Pharm Des. 2006;12(18):2249-70. PMID:16787253
- ↑ Van Gelder P, Dumas F, Bartoldus I, Saint N, Prilipov A, Winterhalter M, Wang Y, Philippsen A, Rosenbusch JP, Schirmer T. Sugar transport through maltoporin of Escherichia coli: role of the greasy slide. J Bacteriol. 2002 Jun;184(11):2994-9. PMID:12003940
- ↑ Basle A, Rummel G, Storici P, Rosenbusch JP, Schirmer T. Crystal structure of osmoporin OmpC from E. coli at 2.0 A. J Mol Biol. 2006 Oct 6;362(5):933-42. Epub 2006 Aug 3. PMID:16949612 doi:10.1016/j.jmb.2006.08.002