3ifx | pdb_00003ifx

Crystal structure of the Spin-labeled KcsA mutant V48R1

spinqualitylabelsall models 3ifx, resolution 3.56Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3ifx is a 4 chain structure with sequence from Streptomyces lividans. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: EPR , Hybrid , X-ray diffraction, Resolution 3.56Å Ligands: K, MTN, TBA 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(+). 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 PubMed Electron spin-echo envelope modulation (ESEEM) spectroscopy is a well-established technique for the study of naturally occurring paramagnetic metal centers. The technique has been used to study copper complexes, hemes, enzyme mechanisms, micellar water content, and water permeation profiles in membranes, among other applications. In the present study, we combine ESEEM spectroscopy with site-directed spin labeling (SDSL) and X-ray crystallography in order to evaluate the technique's potential as a structural tool to describe the native environment of membrane proteins. Using the KcsA potassium channel as a model system, we demonstrate that deuterium ESEEM can detect water permeation along the lipid-exposed surface of the KcsA outer helix. We further demonstrate that (31)P ESEEM is able to identify channel residues that interact with the phosphate headgroup of the lipid bilayer. In combination with X-ray crystallography, the (31)P data may be used to define the phosphate interaction surface of the protein. The results presented here establish ESEEM as a highly informative technique for SDSL studies of membrane proteins. Electron Spin-Echo Envelope Modulation (ESEEM) Reveals Water and Phosphate Interactions with the KcsA Potassium Channel (,).,Cieslak JA, Focia PJ, Gross A Biochemistry. 2010 Feb 2. PMID:20092291 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Potassium channel 3D structures

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