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| | ==Structural basis for maintenance of bacterial outer membrane lipid asymmetry== | | ==Structural basis for maintenance of bacterial outer membrane lipid asymmetry== |
| - | <StructureSection load='5nuo' size='340' side='right' caption='[[5nuo]], [[Resolution|resolution]] 3.20Å' scene=''> | + | <StructureSection load='5nuo' size='340' side='right'caption='[[5nuo]], [[Resolution|resolution]] 3.20Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[5nuo]] is a 6 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_pneumoniae"_(schroeter_1886)_flugge_1886 "bacillus pneumoniae" (schroeter 1886) flugge 1886] and [http://en.wikipedia.org/wiki/Ecoli Ecoli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5NUO OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5NUO FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[5nuo]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12] and [https://en.wikipedia.org/wiki/Klebsiella_pneumoniae Klebsiella pneumoniae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5NUO OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5NUO FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=C8E:(HYDROXYETHYLOXY)TRI(ETHYLOXY)OCTANE'>C8E</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 3.2Å</td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">ompF, cmlB, coa, cry, tolF, b0929, JW0912 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=83333 ECOLI]), mlaA, vacJ, AGG09_21815, BB749_07690, BCB67_11070, BL143_09030, BN49_3944, PMK1_00224, SAMEA3531778_01593, SM30_03044, SM57_02930 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=573 "Bacillus pneumoniae" (Schroeter 1886) Flugge 1886])</td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=C8E:(HYDROXYETHYLOXY)TRI(ETHYLOXY)OCTANE'>C8E</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5nuo FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5nuo OCA], [http://pdbe.org/5nuo PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5nuo RCSB], [http://www.ebi.ac.uk/pdbsum/5nuo PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5nuo ProSAT]</span></td></tr> | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=5nuo FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5nuo OCA], [https://pdbe.org/5nuo PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5nuo RCSB], [https://www.ebi.ac.uk/pdbsum/5nuo PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5nuo ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/OMPF_ECOLI OMPF_ECOLI]] Forms pores that allow passive diffusion of small molecules across the outer membrane. It is also a receptor for the bacteriophage T2.<ref>PMID:19721064</ref> | + | [https://www.uniprot.org/uniprot/OMPF_ECOLI OMPF_ECOLI] Forms pores that allow passive diffusion of small molecules across the outer membrane. It is also a receptor for the bacteriophage T2.<ref>PMID:19721064</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | </div> | | </div> |
| | <div class="pdbe-citations 5nuo" style="background-color:#fffaf0;"></div> | | <div class="pdbe-citations 5nuo" style="background-color:#fffaf0;"></div> |
| | + | |
| | + | ==See Also== |
| | + | *[[Porin 3D structures|Porin 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Ecoli]] | + | [[Category: Escherichia coli K-12]] |
| - | [[Category: Abellon-Ruiz, J]]
| + | [[Category: Klebsiella pneumoniae]] |
| - | [[Category: Basle, A]] | + | [[Category: Large Structures]] |
| - | [[Category: Berg, B van den]] | + | [[Category: Abellon-Ruiz J]] |
| - | [[Category: Bumann, D]] | + | [[Category: Basle A]] |
| - | [[Category: Claudi, B]] | + | [[Category: Bumann D]] |
| - | [[Category: Kaptan, S S]] | + | [[Category: Claudi B]] |
| - | [[Category: Kleinekathofer, U]] | + | [[Category: Kaptan SS]] |
| - | [[Category: Lipid asymmetry]] | + | [[Category: Kleinekathofer U]] |
| - | [[Category: Lipoprotein]] | + | [[Category: Van den Berg B]] |
| - | [[Category: Membrane protein]] | + | |
| - | [[Category: Outer membrane]]
| + | |
| - | [[Category: Phospholipid translocation]]
| + | |
| Structural highlights
Function
OMPF_ECOLI Forms pores that allow passive diffusion of small molecules across the outer membrane. It is also a receptor for the bacteriophage T2.[1]
Publication Abstract from PubMed
The Gram-negative bacterial outer membrane (OM) is a unique bilayer that forms an efficient permeation barrier to protect the cell from noxious compounds 1,2 . The defining characteristic of the OM is lipid asymmetry, with phospholipids comprising the inner leaflet and lipopolysaccharides comprising the outer leaflet 1-3 . This asymmetry is maintained by the Mla pathway, a six-component system that is widespread in Gram-negative bacteria and is thought to mediate retrograde transport of misplaced phospholipids from the outer leaflet of the OM to the cytoplasmic membrane 4 . The OM lipoprotein MlaA performs the first step in this process via an unknown mechanism that does not require external energy input. Here we show, using X-ray crystallography, molecular dynamics simulations and in vitro and in vivo functional assays, that MlaA is a monomeric alpha-helical OM protein that functions as a phospholipid translocation channel, forming a ~20-A-thick doughnut embedded in the inner leaflet of the OM with a central, amphipathic pore. This architecture prevents access of inner leaflet phospholipids to the pore, but allows outer leaflet phospholipids to bind to a pronounced ridge surrounding the channel, followed by diffusion towards the periplasmic space. Enterobacterial MlaA proteins form stable complexes with OmpF/C 5,6 , but the porins do not appear to play an active role in phospholipid transport. MlaA represents a lipid transport protein that selectively removes outer leaflet phospholipids to help maintain the essential barrier function of the bacterial OM.The crystal structure of MlaA, coupled with simulations of its interaction with phospholipids, elucidates how this outer membrane lipoprotein acts as a phospholipid translocation channel to maintain the asymmetric composition of the outer membrane.
Structural basis for maintenance of bacterial outer membrane lipid asymmetry.,Abellon-Ruiz J, Kaptan SS, Basle A, Claudi B, Bumann D, Kleinekathofer U, van den Berg B Nat Microbiol. 2017 Oct 16. doi: 10.1038/s41564-017-0046-x. PMID:29038444[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Duval V, Nicoloff H, Levy SB. Combined inactivation of lon and ycgE decreases multidrug susceptibility by reducing the amount of OmpF porin in Escherichia coli. Antimicrob Agents Chemother. 2009 Nov;53(11):4944-8. doi: 10.1128/AAC.00787-09., Epub 2009 Aug 31. PMID:19721064 doi:10.1128/AAC.00787-09
- ↑ Abellon-Ruiz J, Kaptan SS, Basle A, Claudi B, Bumann D, Kleinekathofer U, van den Berg B. Structural basis for maintenance of bacterial outer membrane lipid asymmetry. Nat Microbiol. 2017 Oct 16. doi: 10.1038/s41564-017-0046-x. PMID:29038444 doi:http://dx.doi.org/10.1038/s41564-017-0046-x
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