1bl8: Difference between revisions
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<StructureSection load='1bl8' size='340' side='right' caption='[[1bl8]], [[Resolution|resolution]] 3.20Å' scene=''> | <StructureSection load='1bl8' size='340' side='right' caption='[[1bl8]], [[Resolution|resolution]] 3.20Å' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[1bl8]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/ | <table><tr><td colspan='2'>[[1bl8]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/"actinomyces_lividans"_krasil'nikov_et_al._1965 "actinomyces lividans" krasil'nikov et al. 1965]. The February 2003 RCSB PDB [http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Potassium Channels'' by Shuchismita Dutta and David S. Goodsell is [http://dx.doi.org/10.2210/rcsb_pdb/mom_2003_2 10.2210/rcsb_pdb/mom_2003_2]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BL8 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1BL8 FirstGlance]. <br> | ||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=K:POTASSIUM+ION'>K</scene></td></tr> | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=K:POTASSIUM+ION'>K</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=1bl8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1bl8 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1bl8 RCSB], [http://www.ebi.ac.uk/pdbsum/1bl8 PDBsum]</span></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=1bl8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1bl8 OCA], [http://pdbe.org/1bl8 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1bl8 RCSB], [http://www.ebi.ac.uk/pdbsum/1bl8 PDBsum]</span></td></tr> | ||
</table> | </table> | ||
== Function == | == Function == | ||
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
</div> | </div> | ||
<div class="pdbe-citations 1bl8" style="background-color:#fffaf0;"></div> | |||
==See Also== | ==See Also== | ||
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__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
[[Category: Actinomyces lividans krasil'nikov et al. 1965]] | |||
[[Category: Potassium Channels]] | [[Category: Potassium Channels]] | ||
[[Category: RCSB PDB Molecule of the Month]] | [[Category: RCSB PDB Molecule of the Month]] | ||
[[Category: Cabral, J M]] | [[Category: Cabral, J M]] | ||
[[Category: Chait, B T]] | [[Category: Chait, B T]] |
Revision as of 16:16, 11 September 2015
POTASSIUM CHANNEL (KCSA) FROM STREPTOMYCES LIVIDANSPOTASSIUM CHANNEL (KCSA) FROM STREPTOMYCES LIVIDANS
Structural highlights
Function[KCSA_STRLI] Acts as a pH-gated potassium ion channel; changing the cytosolic pH from 7 to 4 opens the channel, although it is not clear if this is the physiological stimulus for channel opening. Monovalent cation preference is K(+) > Rb(+) > NH4(+) >> Na(+) > Li(+).[1] 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 PubMedThe potassium channel from Streptomyces lividans is an integral membrane protein with sequence similarity to all known K+ channels, particularly in the pore region. X-ray analysis with data to 3.2 angstroms reveals that four identical subunits create an inverted teepee, or cone, cradling the selectivity filter of the pore in its outer end. The narrow selectivity filter is only 12 angstroms long, whereas the remainder of the pore is wider and lined with hydrophobic amino acids. A large water-filled cavity and helix dipoles are positioned so as to overcome electrostatic destabilization of an ion in the pore at the center of the bilayer. Main chain carbonyl oxygen atoms from the K+ channel signature sequence line the selectivity filter, which is held open by structural constraints to coordinate K+ ions but not smaller Na+ ions. The selectivity filter contains two K+ ions about 7.5 angstroms apart. This configuration promotes ion conduction by exploiting electrostatic repulsive forces to overcome attractive forces between K+ ions and the selectivity filter. The architecture of the pore establishes the physical principles underlying selective K+ conduction. The structure of the potassium channel: molecular basis of K+ conduction and selectivity.,Doyle DA, Morais Cabral J, Pfuetzner RA, Kuo A, Gulbis JM, Cohen SL, Chait BT, MacKinnon R Science. 1998 Apr 3;280(5360):69-77. PMID:9525859[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also
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