2crd

ANALYSIS OF SIDE-CHAIN ORGANIZATION ON A REFINED MODEL OF CHARYBDOTOXIN: STRUCTURAL AND FUNCTIONAL IMPLICATIONS

spinqualitylabelsall models 2crd Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2crd is a 1 chain structure with sequence from Leiurus hebraeus. The February 2003 RCSB PDB Molecule of the Month feature on Potassium Channels by Shuchismita Dutta and David S. Goodsell is 10.2210/rcsb_pdb/mom_2003_2. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Solution NMR, 12 models Ligands: PCA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function KAX11_LEIHE This toxin inhibits numerous potassium channels: shaker (Ki=227 nM), Kv1.2/KCNA2 (nanomolar range), Kv1.3/KCNA3 (nanomolar range), Kv1.5/KCNA5 (Kd>100 nM), Kv1.6/KCNA6 (Ki=22 nM), KCa1.1/KCNMA1 (IC(50)=5.9 nM). It blocks channel activity by a simple bimolecular inhibition process. It also shows a weak interaction with nicotinic acetylcholine receptors (nAChR), suggesting it may weakly inhibit it (PubMed:31276191). It also exhibits pH-specific antimicrobial activities against bacteria (B.subtilis, E.coli and S.aureus) and the fungus C.albicans (PubMed:15118082). 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 The spatial organization of side chains on a refined model of charybdotoxin is presented. First, the structural role of two groups of well-defined, low-accessible side chains (Thr3, Val5, Val16, Leu20, Cys33 and Leu20, His21, Thr23, Cys17, Cys35) is discussed. These side chains are conserved in three out of the five known scorpion toxins acting on K+ channels. Interestingly, they are not conserved in scyllatoxin which presents a slightly different secondary structure organization. Second, the spatial organization of all positively charged residues is analyzed. Comparison with the results presented by Park and Miller [(1992) Biochemistry (preceding paper in this issue)] shows that all functionally important positive residues are located on the beta-sheet side of the toxin. These results are different from those obtained by Auguste et al. [(1992) Biochemistry 31, 648-654] on scyllatoxin, which blocks a different type of K+ channel. This study shows, in fact, that functionally important positive residues are located on the helix side of the toxin. Thus, charybdotoxin and scyllatoxin, which present the same global fold, interact with two different classes of K+ channels by two different parts of the motif. Analysis of side-chain organization on a refined model of charybdotoxin: structural and functional implications.,Bontems F, Gilquin B, Roumestand C, Menez A, Toma F Biochemistry. 1992 Sep 1;31(34):7756-64. PMID:1380828 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Potassium channel toxin 3D structures

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