2abm: Difference between revisions
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[[Image:2abm.gif|left|200px]] | [[Image:2abm.gif|left|200px]] | ||
'''Crystal Structure of Aquaporin Z Tetramer Reveals both Open and Closed Water-conducting Channels''' | {{Structure | ||
|PDB= 2abm |SIZE=350|CAPTION= <scene name='initialview01'>2abm</scene>, resolution 3.20Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=BGL:B-2-OCTYLGLUCOSIDE'>BGL</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene>, <scene name='pdbligand=POQ:BIS(((3S,4S,5R,6R)-5-(ETHYL(PHOSPHORYLOXY))-3,4,6-TRIHYDROXY-TETRAHYDRO-2H-PYRAN-2-YL)METHYL)+HYDROGEN+PHOSPHATE'>POQ</scene>, <scene name='pdbligand=PEE:PHOSPHATIDYLETHANOLAMINE'>PEE</scene>, <scene name='pdbligand=3PG:3-PHOSPHOGLYCERIC+ACID'>3PG</scene> and <scene name='pdbligand=AGA:(1S)-2-{[{[(2S)-2,3-DIHYDROXYPROPYL]OXY}(HYDROXY)PHOSPHORYL]OXY}-1-[(PENTANOYLOXY)METHYL]ETHYL OCTANOATE'>AGA</scene> | |||
|ACTIVITY= | |||
|GENE= aqpZ, bniP ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | |||
}} | |||
'''Crystal Structure of Aquaporin Z Tetramer Reveals both Open and Closed Water-conducting Channels''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
2ABM is a [ | 2ABM is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2ABM OCA]. | ||
==Reference== | ==Reference== | ||
Crystal structure of AqpZ tetramer reveals two distinct Arg-189 conformations associated with water permeation through the narrowest constriction of the water-conducting channel., Jiang J, Daniels BV, Fu D, J Biol Chem. 2006 Jan 6;281(1):454-60. Epub 2005 Oct 20. PMID:[http:// | Crystal structure of AqpZ tetramer reveals two distinct Arg-189 conformations associated with water permeation through the narrowest constriction of the water-conducting channel., Jiang J, Daniels BV, Fu D, J Biol Chem. 2006 Jan 6;281(1):454-60. Epub 2005 Oct 20. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16239219 16239219] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: membrane protein]] | [[Category: membrane protein]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 15:47:50 2008'' | ||
Revision as of 16:47, 20 March 2008
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| , resolution 3.20Å | |||||||
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| Ligands: | , , , , and | ||||||
| Gene: | aqpZ, bniP (Escherichia coli) | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal Structure of Aquaporin Z Tetramer Reveals both Open and Closed Water-conducting Channels
OverviewOverview
AqpZ is a homotetramer of four water-conducting channels that facilitate rapid water movements across the plasma membrane of Escherichia coli. Here we report a 3.2 angstroms crystal structure of the tetrameric AqpZ (tAqpZ). All channel-lining residues in the four monomeric channels are found orientated in nearly identical positions with one marked exception at the narrowest channel constriction, where the side chain of a highly conserved Arg-189 adopts two distinct conformational orientations. In one of the four monomers, the guanidino group of Arg-189 points toward the periplasmic vestibule, opening up the constriction to accommodate the binding of a water molecule through a tridentate H-bond. In the other three monomers, the Arg-189 guanidino group bends over to form an H-bond with carbonyl oxygen of the Thr-183, thus occluding the channel. Therefore, the tAqpZ structure reveals two distinct Arg-189 confirmations associated with water permeation through the channel constrictions. Alternation between the two Arg-189 conformations disrupts continuous flow of water, thus regulating the open probability of the water pore. Further, the difference in Arg-189 displacements is correlated with a strong electron density found between the first transmembrane helices of two open channels, suggesting that the observed Arg-189 conformations are stabilized by asymmetrical subunit interactions in tAqpZ.
About this StructureAbout this Structure
2ABM is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of AqpZ tetramer reveals two distinct Arg-189 conformations associated with water permeation through the narrowest constriction of the water-conducting channel., Jiang J, Daniels BV, Fu D, J Biol Chem. 2006 Jan 6;281(1):454-60. Epub 2005 Oct 20. PMID:16239219
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