1f6g

<StructureSection load='1f6g' size='340' side='right'caption='[[1f6g]], [[NMR_Ensembles_of_Models | 8 NMR models]]' scene=''>

<table><tr><td colspan='2'>[[1f6g]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/"actinomyces_lividans"_krasil'nikov_et_al._1965 "actinomyces lividans" krasil'nikov et al. 1965]. 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='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1bl8|1bl8]]</div></td></tr>

[[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>

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== 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&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 1f6g" style="background-color:#fffaf0;"></div>

[[Category: Actinomyces lividans krasil'nikov et al. 1965]]

[[Category: Cortes, D M]]

[[Category: Perozo, E]]

[[Category: Cytoplasmic domain]]

[[Category: Proton transport]]