7s5x

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Human KATP channel in open conformation, focused on Kir and one SUR, position 1

Structural highlights

7s5x is a 5 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:Electron Microscopy, Resolution 3.7Å
Ligands:ADP, ATP, MG
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Disease

KCJ11_HUMAN MODY;Autosomal dominant hyperinsulinism due to Kir6.2 deficiency;Intermediate DEND syndrome;Transient neonatal diabetes mellitus;Permanent neonatal diabetes mellitus;DEND syndrome;Diazoxide-resistant focal hyperinsulinism due to Kir6.2 deficiency;Autosomal recessive hyperinsulinism due to Kir6.2 deficiency. The disease is caused by mutations affecting the gene represented in this entry. The disease is caused by mutations affecting the gene represented in this entry. The disease is caused by mutations affecting the gene represented in this entry. Defects in KCNJ11 may contribute to non-insulin-dependent diabetes mellitus (NIDDM), also known as diabetes mellitus type 2. The disease is caused by mutations affecting the gene represented in this entry.

Function

KCJ11_HUMAN This receptor is controlled by G proteins. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. Can be blocked by extracellular barium (By similarity). Subunit of ATP-sensitive potassium channels (KATP). Can form cardiac and smooth muscle-type KATP channels with ABCC9. KCNJ11 forms the channel pore while ABCC9 is required for activation and regulation.[1] [2] [3]

Publication Abstract from PubMed

KATP channels are metabolic sensors that translate intracellular ATP/ADP balance into membrane excitability. The molecular composition of KATP includes an inward-rectifier potassium channel (Kir) and an ABC transporter-like sulfonylurea receptor (SUR). Although structures of KATP have been determined in many conformations, in all cases, the pore in Kir is closed. Here, we describe human pancreatic KATP (hKATP) structures with an open pore at 3.1- to 4.0-A resolution using single-particle cryo-electron microscopy (cryo-EM). Pore opening is associated with coordinated structural changes within the ATP-binding site and the channel gate in Kir. Conformational changes in SUR are also observed, resulting in an area reduction of contact surfaces between SUR and Kir. We also observe that pancreatic hKATP exhibits the unique (among inward-rectifier channels) property of PIP2-independent opening, which appears to be correlated with a docked cytoplasmic domain in the absence of PIP2.

Molecular structure of an open human KATP channel.,Zhao C, MacKinnon R Proc Natl Acad Sci U S A. 2021 Nov 30;118(48). pii: 2112267118. doi:, 10.1073/pnas.2112267118. PMID:34815345[4]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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See Also

References

  1. Tammaro P, Ashcroft FM. A mutation in the ATP-binding site of the Kir6.2 subunit of the KATP channel alters coupling with the SUR2A subunit. J Physiol. 2007 Nov 1;584(Pt 3):743-53. doi: 10.1113/jphysiol.2007.143149. Epub, 2007 Sep 13. PMID:17855752 doi:http://dx.doi.org/10.1113/jphysiol.2007.143149
  2. Cooper PE, McClenaghan C, Chen X, Stary-Weinzinger A, Nichols CG. Conserved functional consequences of disease-associated mutations in the slide helix of Kir6.1 and Kir6.2 subunits of the ATP-sensitive potassium channel. J Biol Chem. 2017 Oct 20;292(42):17387-17398. doi: 10.1074/jbc.M117.804971. Epub , 2017 Aug 23. PMID:28842488 doi:http://dx.doi.org/10.1074/jbc.M117.804971
  3. Babenko AP, Gonzalez G, Aguilar-Bryan L, Bryan J. Reconstituted human cardiac KATP channels: functional identity with the native channels from the sarcolemma of human ventricular cells. Circ Res. 1998 Nov 30;83(11):1132-43. PMID:9831708
  4. Zhao C, MacKinnon R. Molecular structure of an open human KATP channel. Proc Natl Acad Sci U S A. 2021 Nov 30;118(48). pii: 2112267118. doi:, 10.1073/pnas.2112267118. PMID:34815345 doi:http://dx.doi.org/10.1073/pnas.2112267118

Contents


PDB ID 7s5x

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