+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-43766 | |||||||||
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Title | Kir6.2-Q52R/SUR1 apo closed channel | |||||||||
Map data | Map of Kir6.2-Q52R SUR1 in an apo closed CTD-down, reconstructed with 12,320 particle C1 local reconstruction. | |||||||||
Sample |
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Keywords | ATP-sensitive potassium channel / KATP channel / SUR1 / Kir6.2-Q52R / potassium transport / metabolic sensor / diabetes / phospholipid binding / PIP2 / TRANSPORT PROTEIN | |||||||||
Function / homology | Function and homology information Regulation of insulin secretion / ATP sensitive Potassium channels / ABC-family proteins mediated transport / response to resveratrol / ventricular cardiac muscle tissue development / ATP-activated inward rectifier potassium channel activity / cell body fiber / inward rectifying potassium channel / sulfonylurea receptor activity / CAMKK-AMPK signaling cascade ...Regulation of insulin secretion / ATP sensitive Potassium channels / ABC-family proteins mediated transport / response to resveratrol / ventricular cardiac muscle tissue development / ATP-activated inward rectifier potassium channel activity / cell body fiber / inward rectifying potassium channel / sulfonylurea receptor activity / CAMKK-AMPK signaling cascade / voltage-gated monoatomic ion channel activity involved in regulation of presynaptic membrane potential / inward rectifier potassium channel activity / ATPase-coupled monoatomic cation transmembrane transporter activity / nervous system process / regulation of monoatomic ion transmembrane transport / inorganic cation transmembrane transport / action potential / ankyrin binding / Ion homeostasis / response to ATP / response to testosterone / potassium ion import across plasma membrane / voltage-gated potassium channel activity / regulation of insulin secretion / axolemma / intercalated disc / negative regulation of insulin secretion / ABC-type transporter activity / potassium ion transmembrane transport / T-tubule / heat shock protein binding / regulation of membrane potential / acrosomal vesicle / response to ischemia / determination of adult lifespan / cellular response to glucose stimulus / positive regulation of protein localization to plasma membrane / sarcolemma / potassium ion transport / cellular response to nicotine / glucose metabolic process / response to estradiol / presynaptic membrane / nuclear envelope / cellular response to tumor necrosis factor / transmembrane transporter binding / response to hypoxia / endosome / response to xenobiotic stimulus / neuronal cell body / glutamatergic synapse / apoptotic process / ATP hydrolysis activity / ATP binding / plasma membrane Similarity search - Function | |||||||||
Biological species | Rattus norvegicus (Norway rat) / Mesocricetus auratus (golden hamster) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 6.9 Å | |||||||||
Authors | Driggers CM / Shyng S-L | |||||||||
Funding support | United States, 2 items
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Citation | Journal: Nat Commun / Year: 2024 Title: Structure of an open K channel reveals tandem PIP binding sites mediating the Kir6.2 and SUR1 regulatory interface. Authors: Camden M Driggers / Yi-Ying Kuo / Phillip Zhu / Assmaa ElSheikh / Show-Ling Shyng / Abstract: ATP-sensitive potassium (K) channels, composed of four pore-lining Kir6.2 subunits and four regulatory sulfonylurea receptor 1 (SUR1) subunits, control insulin secretion in pancreatic β-cells. K ...ATP-sensitive potassium (K) channels, composed of four pore-lining Kir6.2 subunits and four regulatory sulfonylurea receptor 1 (SUR1) subunits, control insulin secretion in pancreatic β-cells. K channel opening is stimulated by PIP and inhibited by ATP. Mutations that increase channel opening by PIP reduce ATP inhibition and cause neonatal diabetes. Although considerable evidence has implicated a role for PIP in K channel function, previously solved open-channel structures have lacked bound PIP, and mechanisms by which PIP regulates K channels remain unresolved. Here, we report the cryoEM structure of a K channel harboring the neonatal diabetes mutation Kir6.2-Q52R, in the open conformation, bound to amphipathic molecules consistent with natural C18:0/C20:4 long-chain PI(4,5)P at two adjacent binding sites between SUR1 and Kir6.2. The canonical PIP binding site is conserved among PIP-gated Kir channels. The non-canonical PIP binding site forms at the interface of Kir6.2 and SUR1. Functional studies demonstrate both binding sites determine channel activity. Kir6.2 pore opening is associated with a twist of the Kir6.2 cytoplasmic domain and a rotation of the N-terminal transmembrane domain of SUR1, which widens the inhibitory ATP binding pocket to disfavor ATP binding. The open conformation is particularly stabilized by the Kir6.2-Q52R residue through cation-π bonding with SUR1-W51. Together, these results uncover the cooperation between SUR1 and Kir6.2 in PIP binding and gating, explain the antagonistic regulation of K channels by PIP and ATP, and provide a putative mechanism by which Kir6.2-Q52R stabilizes an open channel to cause neonatal diabetes. | |||||||||
History |
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-Structure visualization
Supplemental images |
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-Downloads & links
-EMDB archive
Map data | emd_43766.map.gz | 402.2 MB | EMDB map data format | |
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Header (meta data) | emd-43766-v30.xml emd-43766.xml | 22.8 KB 22.8 KB | Display Display | EMDB header |
Images | emd_43766.png | 130.3 KB | ||
Filedesc metadata | emd-43766.cif.gz | 7.4 KB | ||
Others | emd_43766_half_map_1.map.gz emd_43766_half_map_2.map.gz | 764.4 MB 764.3 MB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-43766 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-43766 | HTTPS FTP |
-Related structure data
Related structure data | 8ti1C 8ti2C C: citing same article (ref.) |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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Related items in Molecule of the Month |
-Map
File | Download / File: emd_43766.map.gz / Format: CCP4 / Size: 824 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||
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Annotation | Map of Kir6.2-Q52R SUR1 in an apo closed CTD-down, reconstructed with 12,320 particle C1 local reconstruction. | ||||||||||||||||||||
Voxel size | X=Y=Z: 0.826 Å | ||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||
Details | EMDB XML:
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-Supplemental data
-Half map: Half map A of Kir6.2-Q52R SUR1 in an...
File | emd_43766_half_map_1.map | ||||||||||||
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Annotation | Half map A of Kir6.2-Q52R SUR1 in an apo closed CTD-down, reconstructed with 12,320 particle C1 local reconstruction. | ||||||||||||
Projections & Slices |
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Density Histograms |
-Half map: Half map B of Kir6.2-Q52R SUR1 in an...
File | emd_43766_half_map_2.map | ||||||||||||
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Annotation | Half map B of Kir6.2-Q52R SUR1 in an apo closed CTD-down, reconstructed with 12,320 particle C1 local reconstruction. | ||||||||||||
Projections & Slices |
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Density Histograms |
-Sample components
-Entire : Kir6.2-Q52R/SUR1 open channel
Entire | Name: Kir6.2-Q52R/SUR1 open channel |
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Components |
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-Supramolecule #1: Kir6.2-Q52R/SUR1 open channel
Supramolecule | Name: Kir6.2-Q52R/SUR1 open channel / type: complex / ID: 1 / Parent: 0 / Macromolecule list: all Details: Kir6.2-Q52R/SUR1 open KATP channel in the open conformation in complex with PIP2 and other phospholipids |
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Source (natural) | Organism: Rattus norvegicus (Norway rat) |
Molecular weight | Theoretical: 880 KDa |
-Macromolecule #1: Kir6.2, Potassium inwardly rectifying channel, subfamily J, member 11
Macromolecule | Name: Kir6.2, Potassium inwardly rectifying channel, subfamily J, member 11 type: protein_or_peptide / ID: 1 / Enantiomer: LEVO |
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Source (natural) | Organism: Rattus norvegicus (Norway rat) / Organ: Pancreas / Cell: Beta cell |
Recombinant expression | Organism: Chlorocebus aethiops (grivet) |
Sequence | String: MLSRKGIIPE EYVLTRLAED PTEPRYRTRE RRARFVSKKG NCNVAHKNIR ERGRFLQDVF TTLVDLKWPH TLLIFTMSFL CSWLLFAMV WWLIAFAHGD LAPGEGTNVP CVTSIHSFSS AFLFSIEVQV TIGFGGRMVT EECPLAILIL IVQNIVGLMI N AIMLGCIF ...String: MLSRKGIIPE EYVLTRLAED PTEPRYRTRE RRARFVSKKG NCNVAHKNIR ERGRFLQDVF TTLVDLKWPH TLLIFTMSFL CSWLLFAMV WWLIAFAHGD LAPGEGTNVP CVTSIHSFSS AFLFSIEVQV TIGFGGRMVT EECPLAILIL IVQNIVGLMI N AIMLGCIF MKTAQAHRRA ETLIFSKHAV ITLRHGRLCF MLRVGDLRKS MIISATIHMQ VVRKTTSPEG EVVPLHQVDI PM ENGVGGN SIFLVAPLII YHVIDSNSPL YDLAPSDLHH HQDLEIIVIL EGVVETTGIT TQARTSYLAD EILWGQRFVP IVA EEDGRY SVDYSKFGNT VKVPTPLCTA RQLDEDRSLL DALTLASSRG PLRKRSVAVA KAKPKFSISP DSLS UniProtKB: ATP-sensitive inward rectifier potassium channel 11 |
-Macromolecule #2: SUR1, ATP-binding cassette sub-family C member 8
Macromolecule | Name: SUR1, ATP-binding cassette sub-family C member 8 / type: protein_or_peptide / ID: 2 / Enantiomer: LEVO |
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Source (natural) | Organism: Mesocricetus auratus (golden hamster) |
Recombinant expression | Organism: Chlorocebus aethiops (grivet) |
Sequence | String: MPLAFCGTEN HSAAYRVDQG VLNNGCFVDA LNVVPHVFLL FITFPILFIG WGSQSSKVHI HHSTWLHFPG HNLRWILTFI LLFVLVCEI AEGILSDGVT ESRHLHLYMP AGMAFMAAIT SVVYYHNIET SNFPKLLIAL LIYWTLAFIT KTIKFVKFYD H AIGFSQLR ...String: MPLAFCGTEN HSAAYRVDQG VLNNGCFVDA LNVVPHVFLL FITFPILFIG WGSQSSKVHI HHSTWLHFPG HNLRWILTFI LLFVLVCEI AEGILSDGVT ESRHLHLYMP AGMAFMAAIT SVVYYHNIET SNFPKLLIAL LIYWTLAFIT KTIKFVKFYD H AIGFSQLR FCLTGLLVIL YGMLLLVEVN VIRVRRYIFF KTPREVKPPE DLQDLGVRFL QPFVNLLSKG TYWWMNAFIK TA HKKPIDL RAIGKLPIAM RALTNYQRLC VAFDAQARKD TQSPQGARAI WRALCHAFGR RLILSSTFRI LADLLGFAGP LCI FGIVDH LGKENHVFQP KTQFLGVYFV SSQEFLGNAY VLAVLLFLAL LLQRTFLQAS YYVAIETGIN LRGAIQTKIY NKIM HLSTS NLSMGEMTAG QICNLVAIDT NQLMWFFFLC PNLWAMPVQI IVGVILLYYI LGVSALIGAA VIILLAPVQY FVATK LSQA QRSTLEHSNE RLKQTNEMLR GMKLLKLYAW ESIFCSRVEV TRRKEMTSLR AFAVYTSISI FMNTAIPIAA VLITFV GHV SFFKESDLSP SVAFASLSLF HILVTPLFLL SSVVRSTVKA LVSVQKLSEF LSSAEIREEQ CAPREPAPQG QAGKYQA VP LKVVNRKRPA REEVRDLLGP LQRLAPSMDG DADNFCVQII GGFFTWTPDG IPTLSNITIR IPRGQLTMIV GQVGCGKS S LLLATLGEMQ KVSGAVFWNS NLPDSEGEDP SSPERETAAG SDIRSRGPVA YASQKPWLLN ATVEENITFE SPFNKQRYK MVIEACSLQP DIDILPHGDQ TQIGERGINL SGGQRQRISV ARALYQQTNV VFLDDPFSAL DVHLSDHLMQ AGILELLRDD KRTVVLVTH KLQYLPHADW IIAMKDGTIQ REGTLKDFQR SECQLFEHWK TLMNRQDQEL EKETVMERKA SEPSQGLPRA M SSRDGLLL DEEEEEEEAA ESEEDDNLSS VLHQRAKIPW RACTKYLSSA GILLLSLLVF SQLLKHMVLV AIDYWLAKWT DS ALVLSPA ARNCSLSQEC DLDQSVYAMV FTLLCSLGIV LCLVTSVTVE WTGLKVAKRL HRSLLNRIIL APMRFFETTP LGS ILNRFS SDCNTIDQHI PSTLECLSRS TLLCVSALTV ISYVTPVFLV ALLPLAVVCY FIQKYFRVAS RDLQQLDDTT QLPL LSHFA ETVEGLTTIR AFRYEARFQQ KLLEYTDSNN IASLFLTAAN RWLEVRMEYI GACVVLIAAA TSISNSLHRE LSAGL VGLG LTYALMVSNY LNWMVRNLAD MEIQLGAVKR IHALLKTEAE SYEGLLAPSL IPKNWPDQGK IQIQNLSVRY DSSLKP VLK HVNALISPGQ KIGICGRTGS GKSSFSLAFF RMVDMFEGRI IIDGIDIAKL PLHTLRSRLS IILQDPVLFS GTIRFNL DP EKKCSDSTLW EALEIAQLKL VVKALPGGLD AIITEGGENF SQGQRQLFCL ARAFVRKTSI FIMDEATASI DMATENIL Q KVVMTAFADR TVVTIAHRVH TILSADLVMV LKRGAILEFD KPETLLSQKD SVFASFVRAD K UniProtKB: SUR1 |
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Concentration | 0.15 mg/mL | ||||||||||||||||||
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Buffer | pH: 7.4 Component:
Details: HEPES, pH 7.5, 200 mM NaCl, 100 mM KCl, 0.05% digitonin, long-chain PIP2 | ||||||||||||||||||
Grid | Model: Quantifoil R1.2/1.3 / Material: GOLD / Mesh: 300 / Support film - #0 - Film type ID: 1 / Support film - #0 - Material: GRAPHENE OXIDE / Support film - #0 - topology: CONTINUOUS / Support film - #1 - Film type ID: 2 / Support film - #1 - Material: CARBON / Support film - #1 - topology: HOLEY / Pretreatment - Type: GLOW DISCHARGE / Pretreatment - Time: 45 sec. Details: Following glow-discharge, the grid was coated with Graphene Oxide before sample application | ||||||||||||||||||
Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 279 K / Instrument: FEI VITROBOT MARK III | ||||||||||||||||||
Details | 3 microliters of purified Kir6.2-Q52R/FLAG-SUR1 were loaded onto Quantifoil R 1.2/1.3 Au 300 grids prepared with a fresh Graphene Oxide surface. |
-Electron microscopy
Microscope | FEI TITAN KRIOS |
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Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
Electron optics | C2 aperture diameter: 70.0 µm / Illumination mode: SPOT SCAN / Imaging mode: BRIGHT FIELDBright-field microscopy / Cs: 2.7 mm / Nominal defocus max: 2.5 µm / Nominal defocus min: 1.0 µm / Nominal magnification: 105000 |
Sample stage | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER / Cooling holder cryogen: NITROGEN |
Details | Titan Krios #3 at the Pacific Northwest National Lab |
Image recording | Film or detector model: GATAN K3 (6k x 4k) / Number grids imaged: 3 / Number real images: 5241 / Average exposure time: 2.2 sec. / Average electron dose: 55.0 e/Å2 |
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
-Image processing
Particle selection | Number selected: 12320 / Details: C4 symmetry expanded particles |
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Startup model | Type of model: NONE |
Initial angle assignment | Type: MAXIMUM LIKELIHOOD / Software - Name: cryoSPARC (ver. 4.2.1) |
Final 3D classification | Number classes: 4 / Software - Name: cryoSPARC (ver. 4.2.1) Details: 3D classification parsed out a CTD-down closed conformation |
Final angle assignment | Type: MAXIMUM LIKELIHOOD / Software - Name: cryoSPARC (ver. 4.2.1) |
Final reconstruction | Number classes used: 1 / Applied symmetry - Point group: C1 (asymmetric) / Resolution.type: BY AUTHOR / Resolution: 6.9 Å / Resolution method: FSC 0.143 CUT-OFF / Software - Name: cryoSPARC (ver. 4.2.1) Details: C4 symmetry expanded particles were used for the reconstruction Number images used: 12320 |
-Atomic model buiding 1
Initial model | PDB ID: Chain - Source name: PDB / Chain - Initial model type: experimental model |
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Details | A rigid-body fit of PDB ID 7UQR (closed apo Kir6.2/SUR1) is a good fit into this closed apo Kir6.2-Q52R/SUR1 map |
Refinement | Protocol: RIGID BODY FIT |