2abm: Difference between revisions
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|PDB= 2abm |SIZE=350|CAPTION= <scene name='initialview01'>2abm</scene>, resolution 3.20Å | |PDB= 2abm |SIZE=350|CAPTION= <scene name='initialview01'>2abm</scene>, resolution 3.20Å | ||
|SITE= | |SITE= | ||
|LIGAND= <scene name='pdbligand= | |LIGAND= <scene name='pdbligand=3PG:3-PHOSPHOGLYCERIC+ACID'>3PG</scene>, <scene name='pdbligand=AGA:(1S)-2-{[{[(2S)-2,3-DIHYDROXYPROPYL]OXY}(HYDROXY)PHOSPHORYL]OXY}-1-[(PENTANOYLOXY)METHYL]ETHYL+OCTANOATE'>AGA</scene>, <scene name='pdbligand=BGL:B-2-OCTYLGLUCOSIDE'>BGL</scene>, <scene name='pdbligand=PEE:PHOSPHATIDYLETHANOLAMINE'>PEE</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> | ||
|ACTIVITY= | |ACTIVITY= | ||
|GENE= aqpZ, bniP ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | |GENE= aqpZ, bniP ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | ||
|DOMAIN= | |||
|RELATEDENTRY=[[1fx8|1FX8]], [[1rc2|1RC2]] | |||
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2abm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2abm OCA], [http://www.ebi.ac.uk/pdbsum/2abm PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=2abm RCSB]</span> | |||
}} | }} | ||
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[[Category: Fu, D.]] | [[Category: Fu, D.]] | ||
[[Category: Jiang, J.]] | [[Category: Jiang, J.]] | ||
[[Category: aquaporin]] | [[Category: aquaporin]] | ||
[[Category: membrane protein]] | [[Category: membrane protein]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 01:50:30 2008'' | ||
Revision as of 01:50, 31 March 2008
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| , resolution 3.20Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , , , , | ||||||
| Gene: | aqpZ, bniP (Escherichia coli) | ||||||
| Related: | 1FX8, 1RC2
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| 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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