3pjs | pdb_00003pjs

Mechanism of Activation Gating in the Full-Length KcsA K+ Channel

spinqualitylabelsall models 3pjs, resolution 3.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3pjs is a 8 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. 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(+). Publication Abstract from PubMed Using a constitutively active channel mutant, we solved the structure of full-length KcsA in the open conformation at 3.9 A. The structure reveals that the activation gate expands about 20 A, exerting a strain on the bulge helices in the C-terminal domain and generating side windows large enough to accommodate hydrated K(+) ions. Functional and spectroscopic analysis of the gating transition provides direct insight into the allosteric coupling between the activation gate and the selectivity filter. We show that the movement of the inner gate helix is transmitted to the C-terminus as a straightforward expansion, leading to an upward movement and the insertion of the top third of the bulge helix into the membrane. We suggest that by limiting the extent to which the inner gate can open, the cytoplasmic domain also modulates the level of inactivation occurring at the selectivity filter. Mechanism of activation gating in the full-length KcsA K+ channel.,Uysal S, Cuello LG, Cortes DM, Koide S, Kossiakoff AA, Perozo E Proc Natl Acad Sci U S A. 2011 Jul 5. PMID:21730186 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Antibody 3D structures Potassium channel 3D structures 3D structures of non-human antibody

Proteopedia Page Contributors and Editors (what is this?)

OCA