6c1m

NavAb NormoPP mutantNavAb NormoPP mutant

Structural highlights 6c1m is a 2 chain structure with sequence from Aliarcobacter butzleri RM4018. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.518Å Ligands: , , , , Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function A8EVM5_ALIB4 Publication Abstract from PubMed Potassium-sensitive hypokalaemic and normokalaemic periodic paralysis are inherited skeletal muscle diseases characterized by episodes of flaccid muscle weakness(1,2). They are caused by single mutations in positively charged residues ('gating charges') in the S4 transmembrane segment of the voltage sensor of the voltage-gated sodium channel Nav1.4 or the calcium channel Cav1.1(1,2). Mutations of the outermost gating charges (R1 and R2) cause hypokalaemic periodic paralysis(1,2) by creating a pathogenic gating pore in the voltage sensor through which cations leak in the resting state(3,4). Mutations of the third gating charge (R3) cause normokalaemic periodic paralysis (5) owing to cation leak in both activated and inactivated states (6) . Here we present high-resolution structures of the model bacterial sodium channel NavAb with the analogous gating-charge mutations(7,8), which have similar functional effects as in the human channels. The R2G and R3G mutations have no effect on the backbone structures of the voltage sensor, but they create an aqueous cavity near the hydrophobic constriction site that controls gating charge movement through the voltage sensor. The R3G mutation extends the extracellular aqueous cleft through the entire length of the activated voltage sensor, creating an aqueous path through the membrane. Conversely, molecular modelling shows that the R2G mutation creates a continuous aqueous path through the membrane only in the resting state. Crystal structures of NavAb(R2G) in complex with guanidinium define a potential drug target site. Molecular dynamics simulations illustrate the mechanism of Na(+) permeation through the mutant gating pore in concert with conformational fluctuations of the gating charge R4. Our results reveal pathogenic mechanisms of periodic paralysis at the atomic level and suggest designs of drugs that may prevent ionic leak and provide symptomatic relief from hypokalaemic and normokalaemic periodic paralysis. Structural basis for gating pore current in periodic paralysis.,Jiang D, Gamal El-Din TM, Ing C, Lu P, Pomes R, Zheng N, Catterall WA Nature. 2018 May;557(7706):590-594. doi: 10.1038/s41586-018-0120-4. Epub 2018 May, 16. PMID:29769724 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ion channels 3D structures

spinqualitylabelsall models 6c1m, resolution 2.52Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image