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4lcu

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Revision as of 01:08, 5 August 2016

Structure of KcsA with E118A mutation

Structural highlights

4lcu is a 3 chain structure with sequence from "actinomyces_lividans"_krasil'nikov_et_al._1965 "actinomyces lividans" krasil'nikov et al. 1965 and Lk3 transgenic mice. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	,
Related:	4lbe
Gene:	kcsA, skc1 ("Actinomyces lividans" Krasil'nikov et al. 1965)
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

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]

Publication Abstract from PubMed

The bacterial potassium channel KcsA is gated open by the binding of protons to amino acids on the intracellular side of the channel. We have identified, via channel mutagenesis and x-ray crystallography, two pH-sensing amino acids and a set of nearby residues involved in molecular interactions that influence gating. We found that the minimal mutation of one histidine (H25) and one glutamate (E118) near the cytoplasmic gate completely abolished pH-dependent gating. Mutation of nearby residues either alone or in pairs altered the channel's response to pH. In addition, mutations of certain pairs of residues dramatically increased the energy barriers between the closed and open states. We proposed a Monod-Wyman-Changeux model for proton binding and pH-dependent gating in KcsA, where H25 is a "strong" sensor displaying a large shift in pKa between closed and open states, and E118 is a "weak" pH sensor. Modifying model parameters that are involved in either the intrinsic gating equilibrium or the pKa values of the pH-sensing residues was sufficient to capture the effects of all mutations.

Molecular interactions involved in proton-dependent gating in KcsA potassium channels.,Posson DJ, Thompson AN, McCoy JG, Nimigean CM J Gen Physiol. 2013 Dec;142(6):613-24. doi: 10.1085/jgp.201311057. Epub 2013 Nov , 11. PMID:24218397^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Schrempf H, Schmidt O, Kummerlen R, Hinnah S, Muller D, Betzler M, Steinkamp T, Wagner R. A prokaryotic potassium ion channel with two predicted transmembrane segments from Streptomyces lividans. EMBO J. 1995 Nov 1;14(21):5170-8. PMID:7489706
↑ Posson DJ, Thompson AN, McCoy JG, Nimigean CM. Molecular interactions involved in proton-dependent gating in KcsA potassium channels. J Gen Physiol. 2013 Dec;142(6):613-24. doi: 10.1085/jgp.201311057. Epub 2013 Nov , 11. PMID:24218397 doi:http://dx.doi.org/10.1085/jgp.201311057

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 See Also
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/4lcu"

@@ Line 1: / Line 1: @@
 ==Structure of KcsA with E118A mutation==
 <StructureSection load='4lcu' size='340' side='right' caption='[[4lcu]], [[Resolution|resolution]] 2.75&Aring;' scene=''>
@@ Line 6: / Line 7: @@
 <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4lbe|4lbe]]</td></tr>
 <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">kcsA, skc1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1916 "Actinomyces lividans" Krasil'nikov et al. 1965])</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=4lcu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4lcu OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4lcu RCSB], [http://www.ebi.ac.uk/pdbsum/4lcu 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=4lcu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4lcu OCA], [http://pdbe.org/4lcu PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4lcu RCSB], [http://www.ebi.ac.uk/pdbsum/4lcu PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4lcu ProSAT]</span></td></tr>
 </table>
 == Function ==
@@ Line 18: / Line 19: @@
 From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
 </div>
+<div class="pdbe-citations 4lcu" style="background-color:#fffaf0;"></div>
+==See Also==
+*[[Potassium Channel|Potassium Channel]]
 == References ==
 <references/>

4lcu

From Proteopedia

Revision as of 01:08, 5 August 2016

Structure of KcsA with E118A mutation

Structural highlights

Function

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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