|
|
| (2 intermediate revisions not shown.) |
| Line 1: |
Line 1: |
| | | | |
| | ==Main porin from Mycobacterium smegmatis (MspA)== | | ==Main porin from Mycobacterium smegmatis (MspA)== |
| - | <StructureSection load='1uun' size='340' side='right' caption='[[1uun]], [[Resolution|resolution]] 2.50Å' scene=''> | + | <StructureSection load='1uun' size='340' side='right'caption='[[1uun]], [[Resolution|resolution]] 2.50Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[1uun]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_smegmatis"_trevisan_1889 "bacillus smegmatis" trevisan 1889]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1UUN OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1UUN FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[1uun]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Mycolicibacterium_smegmatis Mycolicibacterium smegmatis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1UUN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1UUN FirstGlance]. <br> |
| - | </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=1uun FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1uun OCA], [http://pdbe.org/1uun PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1uun RCSB], [http://www.ebi.ac.uk/pdbsum/1uun PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1uun ProSAT]</span></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]] 2.5Å</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=1uun FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1uun OCA], [https://pdbe.org/1uun PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1uun RCSB], [https://www.ebi.ac.uk/pdbsum/1uun PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1uun ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/MSPA_MYCS2 MSPA_MYCS2]] The major porin in this organism, forms a water-filled channel which favors the permeation of cations, amino acids, iron Fe(3+) and less efficiently phosphate. Does not transport Fe-ExoMS, the predominant siderophore. Plays a role in transport of beta-lactamase and hydrophilic fluoroquinolone antibiotics such as norfloxacin as well as chloramphenicol. There are about 2400 porins in wild-type, 800 in an mspA deletion and 150 in a double mspA-mspC deletion. Different conductance values with maxima at 2.3 and 4.6 nanosiemens might be caused by a simultaneous reconstitution of MspA channels into the membrane or by the existence of different MspA conformations.<ref>PMID:10476028</ref> <ref>PMID:16238622</ref> <ref>PMID:17209034</ref> <ref>PMID:18559650</ref> <ref>PMID:20952578</ref> | + | [https://www.uniprot.org/uniprot/MSPA_MYCS2 MSPA_MYCS2] The major porin in this organism, forms a water-filled channel which favors the permeation of cations, amino acids, iron Fe(3+) and less efficiently phosphate. Does not transport Fe-ExoMS, the predominant siderophore. Plays a role in transport of beta-lactamase and hydrophilic fluoroquinolone antibiotics such as norfloxacin as well as chloramphenicol. There are about 2400 porins in wild-type, 800 in an mspA deletion and 150 in a double mspA-mspC deletion. Different conductance values with maxima at 2.3 and 4.6 nanosiemens might be caused by a simultaneous reconstitution of MspA channels into the membrane or by the existence of different MspA conformations.<ref>PMID:10476028</ref> <ref>PMID:16238622</ref> <ref>PMID:17209034</ref> <ref>PMID:18559650</ref> <ref>PMID:20952578</ref> |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
| Line 29: |
Line 30: |
| | | | |
| | ==See Also== | | ==See Also== |
| - | *[[Porin|Porin]] | + | *[[Porin 3D structures|Porin 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Bacillus smegmatis trevisan 1889]] | + | [[Category: Large Structures]] |
| - | [[Category: Faller, M]] | + | [[Category: Mycolicibacterium smegmatis]] |
| - | [[Category: Niederweis, M]] | + | [[Category: Faller M]] |
| - | [[Category: Schulz, G E]] | + | [[Category: Niederweis M]] |
| - | [[Category: Mycobacteria]] | + | [[Category: Schulz GE]] |
| - | [[Category: Porin]]
| + | |
| Structural highlights
Function
MSPA_MYCS2 The major porin in this organism, forms a water-filled channel which favors the permeation of cations, amino acids, iron Fe(3+) and less efficiently phosphate. Does not transport Fe-ExoMS, the predominant siderophore. Plays a role in transport of beta-lactamase and hydrophilic fluoroquinolone antibiotics such as norfloxacin as well as chloramphenicol. There are about 2400 porins in wild-type, 800 in an mspA deletion and 150 in a double mspA-mspC deletion. Different conductance values with maxima at 2.3 and 4.6 nanosiemens might be caused by a simultaneous reconstitution of MspA channels into the membrane or by the existence of different MspA conformations.[1] [2] [3] [4] [5]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Mycobacteria have low-permeability outer membranes that render them resistant to most antibiotics. Hydrophilic nutrients can enter by way of transmembrane-channel proteins called porins. An x-ray analysis of the main porin from Mycobacterium smegmatis, MspA, revealed a homooctameric goblet-like conformation with a single central channel. This is the first structure of a mycobacterial outer-membrane protein. No structure-related protein was found in the Protein Data Bank. MspA contains two consecutive beta barrels with nonpolar outer surfaces that form a ribbon around the porin, which is too narrow to fit the thickness of the mycobacterial outer membrane in contemporary models.
The structure of a mycobacterial outer-membrane channel.,Faller M, Niederweis M, Schulz GE Science. 2004 Feb 20;303(5661):1189-92. PMID:14976314[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Niederweis M, Ehrt S, Heinz C, Klocker U, Karosi S, Swiderek KM, Riley LW, Benz R. Cloning of the mspA gene encoding a porin from Mycobacterium smegmatis. Mol Microbiol. 1999 Sep;33(5):933-45. PMID:10476028
- ↑ Stephan J, Bender J, Wolschendorf F, Hoffmann C, Roth E, Mailander C, Engelhardt H, Niederweis M. The growth rate of Mycobacterium smegmatis depends on sufficient porin-mediated influx of nutrients. Mol Microbiol. 2005 Nov;58(3):714-30. PMID:16238622 doi:http://dx.doi.org/10.1111/j.1365-2958.2005.04878.x
- ↑ Wolschendorf F, Mahfoud M, Niederweis M. Porins are required for uptake of phosphates by Mycobacterium smegmatis. J Bacteriol. 2007 Mar;189(6):2435-42. Epub 2007 Jan 5. PMID:17209034 doi:http://dx.doi.org/10.1128/JB.01600-06
- ↑ Danilchanka O, Pavlenok M, Niederweis M. Role of porins for uptake of antibiotics by Mycobacterium smegmatis. Antimicrob Agents Chemother. 2008 Sep;52(9):3127-34. doi: 10.1128/AAC.00239-08., Epub 2008 Jun 16. PMID:18559650 doi:http://dx.doi.org/10.1128/AAC.00239-08
- ↑ Jones CM, Niederweis M. Role of porins in iron uptake by Mycobacterium smegmatis. J Bacteriol. 2010 Dec;192(24):6411-7. doi: 10.1128/JB.00986-10. Epub 2010 Oct 15. PMID:20952578 doi:http://dx.doi.org/10.1128/JB.00986-10
- ↑ Faller M, Niederweis M, Schulz GE. The structure of a mycobacterial outer-membrane channel. Science. 2004 Feb 20;303(5661):1189-92. PMID:14976314 doi:10.1126/science.1094114
|
