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Open data
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Basic information
Entry | Database: EMDB / ID: EMD-21036 | |||||||||
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Title | Cryo-EM structure of Ca2+-free hsSlo1 channel | |||||||||
![]() | B-factor-sharpened cryo-EM map of Ca2 -free hsSlo1 | |||||||||
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![]() | High conductance Ca2+-activated K+ channel / Slo1 channel / ![]() ![]() | |||||||||
Function / homology | ![]() Acetylcholine inhibits contraction of outer hair cells / ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Similarity search - Function | |||||||||
Biological species | ![]() ![]() | |||||||||
Method | ![]() ![]() | |||||||||
![]() | Tao X / MacKinnon R | |||||||||
Funding support | ![]()
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![]() | ![]() Title: Molecular structures of the human Slo1 K channel in complex with β4. Authors: Xiao Tao / Roderick MacKinnon / ![]() Abstract: Slo1 is a Ca- and voltage-activated K channel that underlies skeletal and smooth muscle contraction, audition, hormone secretion and neurotransmitter release. In mammals, Slo1 is regulated by ...Slo1 is a Ca- and voltage-activated K channel that underlies skeletal and smooth muscle contraction, audition, hormone secretion and neurotransmitter release. In mammals, Slo1 is regulated by auxiliary proteins that confer tissue-specific gating and pharmacological properties. This study presents cryo-EM structures of Slo1 in complex with the auxiliary protein, β4. Four β4, each containing two transmembrane helices, encircle Slo1, contacting it through helical interactions inside the membrane. On the extracellular side, β4 forms a tetrameric crown over the pore. Structures with high and low Ca concentrations show that identical gating conformations occur in the absence and presence of β4, implying that β4 serves to modulate the relative stabilities of 'pre-existing' conformations rather than creating new ones. The effects of β4 on scorpion toxin inhibition kinetics are explained by the crown, which constrains access but does not prevent binding. | |||||||||
History |
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Structure visualization
Movie |
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Structure viewer | EM map: ![]() ![]() ![]() |
Supplemental images |
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Downloads & links
-EMDB archive
Map data | ![]() | 45.7 MB | ![]() | |
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Header (meta data) | ![]() ![]() | 15.6 KB 15.6 KB | Display Display | ![]() |
Images | ![]() | 187.1 KB | ||
Filedesc metadata | ![]() | 6.5 KB | ||
Archive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 6v3gMC ![]() 6v22C ![]() 6v35C ![]() 6v38C C: citing same article ( M: atomic model generated by this map |
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Similar structure data |
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Links
EMDB pages | ![]() ![]() |
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Related items in Molecule of the Month |
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Map
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Annotation | B-factor-sharpened cryo-EM map of Ca2 -free hsSlo1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 1.3 Å | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
CCP4 map header:
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-Supplemental data
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Sample components
-Entire : Ca2+-free hsSlo1 channel
Entire | Name: Ca2+-free hsSlo1 channel |
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Components |
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-Supramolecule #1: Ca2+-free hsSlo1 channel
Supramolecule | Name: Ca2+-free hsSlo1 channel / type: complex / ID: 1 / Parent: 0 / Macromolecule list: all Details: human high conductance Ca2+-activated K+ channel Slo1 (BK) in the absence of Calcium |
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Source (natural) | Organism: ![]() ![]() |
-Macromolecule #1: Calcium-activated potassium channel subunit alpha-1
Macromolecule | Name: Calcium-activated potassium channel subunit alpha-1 / type: protein_or_peptide / ID: 1 / Number of copies: 4 / Enantiomer: LEVO |
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Source (natural) | Organism: ![]() ![]() |
Molecular weight | Theoretical: 119.988062 KDa |
Recombinant expression | Organism: ![]() ![]() |
Sequence | String: MDALIIPVTM EVPCDSRGQR MWWAFLASSM VTFFGGLFII LLWRTLKYLW TVCCHCGGKT KEAQKINNGS SQADGTLKPV DEKEEAVAA EVGWMTSVKD WAGVMISAQT LTGRVLVVLV FALSIGALVI YFIDSSNPIE SCQNFYKDFT LQIDMAFNVF F LLYFGLRF ...String: MDALIIPVTM EVPCDSRGQR MWWAFLASSM VTFFGGLFII LLWRTLKYLW TVCCHCGGKT KEAQKINNGS SQADGTLKPV DEKEEAVAA EVGWMTSVKD WAGVMISAQT LTGRVLVVLV FALSIGALVI YFIDSSNPIE SCQNFYKDFT LQIDMAFNVF F LLYFGLRF IAANDKLWFW LEVNSVVDFF TVPPVFVSVY LNRSWLGLRF LRALRLIQFS EILQFLNILK TSNSIKLVNL LS IFISTWL TAAGFIHLVE NSGDPWENFQ NNQALTYWEC VYLLMVTMST VGYGDVYAKT TLGRLFMVFF ILGGLAMFAS YVP EIIELI GNRKKYGGSY SAVSGRKHIV VCGHITLESV SNFLKDFLHK DRDDVNVEIV FLHNISPNLE LEALFKRHFT QVEF YQGSV LNPHDLARVK IESADACLIL ANKYCADPDA EDASNIMRVI SIKNYHPKIR IITQMLQYHN KAHLLNIPSW NWKEG DDAI CLAELKLGFI AQSCLAQGLS TMLANLFSMR SFIKIEEDTW QKYYLEGVSN EMYTEYLSSA FVGLSFPTVC ELCFVK LKL LMIAIEYKSA NRESRILINP GNHLKIQEGT LGFFIASDAK EVKRAFFYCK ACHDDITDPK RIKKCGCKRL EDEQPST LS PKKKQRNGGM RNSPNTSPKL MRHDPLLIPG NDQIDNMDSN VKKYDSTGMF HWCAPKEIEK VILTRSEAAM TVLSGHVV V CIFGDVSSAL IGLRNLVMPL RASNFHYHEL KHIVFVGSIE YLKREWETLH NFPKVSILPG TPLSRADLRA VNINLCDMC VILSANQNNI DDTSLQDKEC ILASLNIKSM QFDDSIGVLQ ANSQGFTPPG MDRSSPDNSP VHGMLRQPSI TTGVNIPIIT ELVNDTNVQ FLDQDDDDDP DTELYLTQPF ACGTAFAVSV LDSLMSATYF NDNILTLIRT LVTGGATPEL EALIAEENAL R GGYSTPQT LANRDRCRVA QLALLDGPFA DLGDGGCYGD LFCKALKTYN MLCFGIYRLR DAHLSTPSQC TKRYVITNPP YE FELVPTD LIFCLMQFDS NSLEVLFQ UniProtKB: ![]() |
-Experimental details
-Structure determination
Method | ![]() |
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Aggregation state | particle |
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Sample preparation
Concentration | 8.5 mg/mL | ||||||||||||||||||
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Buffer | pH: 8 Component:
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Grid | Model: Quantifoil R1.2/1.3 / Material: GOLD / Mesh: 400 / Support film - Material: CARBON / Support film - topology: HOLEY / Pretreatment - Type: GLOW DISCHARGE / Pretreatment - Time: 12 sec. / Pretreatment - Atmosphere: AIR | ||||||||||||||||||
Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 295 K / Instrument: FEI VITROBOT MARK IV / Details: Blot for 4 seconds before plunging.. |
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Electron microscopy
Microscope | FEI TITAN KRIOS |
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Electron beam | Acceleration voltage: 300 kV / Electron source: ![]() |
Electron optics | C2 aperture diameter: 70.0 µm / Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD![]() |
Sample stage | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER / Cooling holder cryogen: NITROGEN |
Image recording | Film or detector model: GATAN K2 SUMMIT (4k x 4k) / Detector mode: SUPER-RESOLUTION / Digitization - Frames/image: 1-50 / Number grids imaged: 1 / Number real images: 1292 / Average exposure time: 15.0 sec. / Average electron dose: 89.0 e/Å2 |
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Image processing
Startup model | Type of model: NONE |
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Initial angle assignment | Type: PROJECTION MATCHING / Software - Name: cryoSPARC (ver. 2.9.0) |
Final 3D classification | Number classes: 3 / Software - Name: RELION (ver. 3.0.8) |
Final angle assignment | Type: PROJECTION MATCHING / Software - Name: FREALIGN (ver. 9.11) |
Final reconstruction | Applied symmetry - Point group: C4 (4 fold cyclic![]() |
-Atomic model buiding 1
Initial model | PDB ID: Chain - Source name: PDB / Chain - Initial model type: experimental model |
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Refinement | Space: REAL / Protocol: RIGID BODY FIT |
Output model | ![]() PDB-6v3g: |
-Atomic model buiding 2
Refinement | Space: REAL / Protocol: AB INITIO MODEL |
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Output model | ![]() PDB-6v3g: |