1f6g: Difference between revisions
New page: left|200px<br /> <applet load="1f6g" size="450" color="white" frame="true" align="right" spinBox="true" caption="1f6g" /> '''POTASSIUM CHANNEL (KCSA) FULL-LENGTH FOLD''... |
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== | ==POTASSIUM CHANNEL (KCSA) FULL-LENGTH FOLD== | ||
The molecular architecture of the NH(2) and COOH termini of the | <StructureSection load='1f6g' size='340' side='right'caption='[[1f6g]]' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1f6g]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Streptomyces_lividans Streptomyces lividans]. The February 2003 RCSB PDB [https://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 [https://dx.doi.org/10.2210/rcsb_pdb/mom_2003_2 10.2210/rcsb_pdb/mom_2003_2]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1F6G OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1F6G FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</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=1f6g FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1f6g OCA], [https://pdbe.org/1f6g PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1f6g RCSB], [https://www.ebi.ac.uk/pdbsum/1f6g PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1f6g ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/KCSA_STRLI 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(+).<ref>PMID:7489706</ref> | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/f6/1f6g_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1f6g ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The molecular architecture of the NH(2) and COOH termini of the prokaryotic potassium channel KcsA has been determined using site-directed spin-labeling methods and paramagnetic resonance EPR spectroscopy. Cysteine mutants were generated (residues 5-24 and 121-160) and spin labeled, and the X-band CW EPR spectra were obtained from liposome-reconstituted channels at room temperature. Data on probe mobility (DeltaHo(-1)), accessibility parameters (PiO(2) and PiNiEdda), and inter-subunit spin-spin interaction (Omega) were used as structural constraints to build a three-dimensional folding model of these cytoplasmic domains from a set of simulated annealing and restrained molecular dynamics runs. 32 backbone structures were generated and averaged using fourfold symmetry, and a final mean structure was obtained from the eight lowest energy runs. Based on the present data, together with information from the KcsA crystal structure, a model for the three-dimensional fold of full-length KcsA was constructed. In this model, the NH(2) terminus of KcsA forms an alpha-helix anchored at the membrane-water interface, while the COOH terminus forms a right-handed four-helix bundle that extend some 40-50 A towards the cytoplasm. Functional analysis of COOH-terminal deletion constructs suggest that, while the COOH terminus does not play a substantial role in determining ion permeation properties, it exerts a modulatory role in the pH-dependent gating mechanism. | |||
Molecular architecture of full-length KcsA: role of cytoplasmic domains in ion permeation and activation gating.,Cortes DM, Cuello LG, Perozo E J Gen Physiol. 2001 Feb;117(2):165-80. PMID:11158168<ref>PMID:11158168</ref> | |||
== | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
</div> | |||
<div class="pdbe-citations 1f6g" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Potassium channel 3D structures|Potassium channel 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Potassium Channels]] | [[Category: Potassium Channels]] | ||
[[Category: | [[Category: RCSB PDB Molecule of the Month]] | ||
[[Category: Streptomyces lividans]] | [[Category: Streptomyces lividans]] | ||
[[Category: Cortes | [[Category: Cortes DM]] | ||
[[Category: Perozo | [[Category: Perozo E]] | ||
