[English] 日本語
Yorodumi
- PDB-9o85: Cryo-EM structure of KCa2.2_I/calmodulin channel in complex with ... -

+
Open data


ID or keywords:

Loading...

-
Basic information

Entry
Database: PDB / ID: 9o85
TitleCryo-EM structure of KCa2.2_I/calmodulin channel in complex with rimtuzalcap
Components
  • Calmodulin-1
  • Small conductance calcium-activated potassium channel protein 2
KeywordsTRANSPORT PROTEIN / Ion channel / Small-conductance calcium-activated potassium channel / Membrane protein
Function / homology
Function and homology information


Ca2+ activated K+ channels / small conductance calcium-activated potassium channel activity / membrane repolarization during atrial cardiac muscle cell action potential / calcium-activated potassium channel activity / establishment of protein localization to mitochondrial membrane / type 3 metabotropic glutamate receptor binding / positive regulation of potassium ion transport / inward rectifier potassium channel activity / establishment of protein localization to membrane / regulation of potassium ion transmembrane transport ...Ca2+ activated K+ channels / small conductance calcium-activated potassium channel activity / membrane repolarization during atrial cardiac muscle cell action potential / calcium-activated potassium channel activity / establishment of protein localization to mitochondrial membrane / type 3 metabotropic glutamate receptor binding / positive regulation of potassium ion transport / inward rectifier potassium channel activity / establishment of protein localization to membrane / regulation of potassium ion transmembrane transport / nitric-oxide synthase binding / organelle localization by membrane tethering / mitochondrion-endoplasmic reticulum membrane tethering / autophagosome membrane docking / regulation of synaptic vesicle exocytosis / presynaptic endocytosis / regulation of cardiac muscle cell action potential / negative regulation of ryanodine-sensitive calcium-release channel activity / alpha-actinin binding / calcineurin-mediated signaling / regulation of synaptic vesicle endocytosis / regulation of neuronal synaptic plasticity / protein phosphatase activator activity / postsynaptic cytosol / adenylate cyclase binding / regulation of ryanodine-sensitive calcium-release channel activity / catalytic complex / detection of calcium ion / regulation of cardiac muscle contraction / phosphatidylinositol 3-kinase binding / smooth endoplasmic reticulum / presynaptic cytosol / calcium channel inhibitor activity / cellular response to interferon-beta / regulation of release of sequestered calcium ion into cytosol by sarcoplasmic reticulum / titin binding / voltage-gated potassium channel complex / calcium channel regulator activity / potassium ion transmembrane transport / T-tubule / sperm midpiece / calcium channel complex / calyx of Held / nitric-oxide synthase regulator activity / response to amphetamine / adenylate cyclase activator activity / regulation of heart rate / protein serine/threonine kinase activator activity / sarcomere / regulation of cytokinesis / positive regulation of receptor signaling pathway via JAK-STAT / spindle microtubule / modulation of chemical synaptic transmission / potassium ion transport / sarcolemma / Schaffer collateral - CA1 synapse / cellular response to type II interferon / Z disc / response to calcium ion / spindle pole / calcium-dependent protein binding / G2/M transition of mitotic cell cycle / myelin sheath / growth cone / dendritic spine / transmembrane transporter binding / postsynaptic membrane / calmodulin binding / protein domain specific binding / neuronal cell body / centrosome / calcium ion binding / protein kinase binding / glutamatergic synapse / cell surface / protein homodimerization activity / protein-containing complex / mitochondrion / nucleoplasm / membrane / plasma membrane / cytosol / cytoplasm
Similarity search - Function
Calmodulin-binding domain / Potassium channel, calcium-activated, SK / SK, calmodulin-binding domain superfamily / Calmodulin binding domain / Calcium-activated SK potassium channel / Calmodulin binding domain / Potassium channel domain / Ion channel / : / EF-hand domain pair ...Calmodulin-binding domain / Potassium channel, calcium-activated, SK / SK, calmodulin-binding domain superfamily / Calmodulin binding domain / Calcium-activated SK potassium channel / Calmodulin binding domain / Potassium channel domain / Ion channel / : / EF-hand domain pair / EF-hand, calcium binding motif / EF-Hand 1, calcium-binding site / EF-hand calcium-binding domain. / EF-hand calcium-binding domain profile. / EF-hand domain / EF-hand domain pair
Similarity search - Domain/homology
: / : / Calmodulin-1 / Small conductance calcium-activated potassium channel protein 2
Similarity search - Component
Biological speciesRattus norvegicus (Norway rat)
MethodELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.13 Å
AuthorsNam, Y.W. / Zhang, M.
Funding support United States, 4items
OrganizationGrant numberCountry
American Heart Association23AIREA1039423 United States
American Heart Association24CDA1260237 United States
National Institutes of Health/National Institute of Neurological Disorders and Stroke (NIH/NINDS)4R33 NS101182-03 United States
National Institutes of Health/National Institute of Neurological Disorders and Stroke (NIH/NINDS)R15 NS130420-01A1 United States
CitationJournal: Res Sq / Year: 2025
Title: Structural basis for the subtype-selectivity of K2.2 channel activators.
Authors: Miao Zhang / Young-Woo Nam / Alena Ramanishka / Yang Xu / Rose Marie Yasuda / Dohyun Im / Meng Cui / George Chandy / Heike Wulff /
Abstract: Small-conductance (K2.2) and intermediate-conductance (K3.1) Ca-activated K channels are gated by a Ca-calmodulin dependent mechanism. NS309 potentiates the activity of both K2.2 and K3.1, while ...Small-conductance (K2.2) and intermediate-conductance (K3.1) Ca-activated K channels are gated by a Ca-calmodulin dependent mechanism. NS309 potentiates the activity of both K2.2 and K3.1, while rimtuzalcap selectively activates K2.2. Rimtuzalcap has been used in clinical trials for the treatment of spinocerebellar ataxia and essential tremor. We report cryo-electron microscopy structures of K2.2 channels bound with NS309 and rimtuzalcap, in addition to K3.1 channels with NS309. The different conformations of calmodulin and the cytoplasmic HC helices in the two channels underlie the subtype-selectivity of rimtuzalcap for K2.2. Calmodulin's N-lobes in the K2.2 structure are far apart and undergo conformational changes to accommodate either NS309 or rimtuzalcap. Calmodulin's Nlobes in the K3.1 structure are closer to each other and are constrained by the HC helices of K3.1, which allows binding of NS309 but not of the bulkier rimtuzalcap. These structures provide a framework for structure-based drug design targeting K2.2 channels.
History
DepositionApr 15, 2025Deposition site: RCSB / Processing site: RCSB
Revision 1.0Jun 18, 2025Provider: repository / Type: Initial release

-
Structure visualization

Structure viewerMolecule:
MolmilJmol/JSmol

Downloads & links

-
Assembly

Deposited unit
A: Small conductance calcium-activated potassium channel protein 2
B: Small conductance calcium-activated potassium channel protein 2
C: Small conductance calcium-activated potassium channel protein 2
D: Small conductance calcium-activated potassium channel protein 2
E: Calmodulin-1
F: Calmodulin-1
G: Calmodulin-1
H: Calmodulin-1
hetero molecules


Theoretical massNumber of molelcules
Total (without water)240,46023
Polymers238,5098
Non-polymers1,95215
Water1448
1


  • Idetical with deposited unit
  • defined by author
  • Evidence: electron microscopy, not applicable
TypeNameSymmetry operationNumber
identity operation1_5551

-
Components

-
Protein , 2 types, 8 molecules ABCDEFGH

#1: Protein
Small conductance calcium-activated potassium channel protein 2 / SK2 / SKCa 2 / SKCa2 / KCa2.2


Mass: 43349.289 Da / Num. of mol.: 4 / Fragment: UNP residues 121-500
Source method: isolated from a genetically manipulated source
Source: (gene. exp.) Rattus norvegicus (Norway rat) / Gene: Kcnn2 / Production host: Homo sapiens (human) / References: UniProt: P70604
#2: Protein
Calmodulin-1


Mass: 16277.873 Da / Num. of mol.: 4
Source method: isolated from a genetically manipulated source
Source: (gene. exp.) Rattus norvegicus (Norway rat) / Gene: Calm1, Calm, Cam, Cam1, CaMI / Production host: Homo sapiens (human) / References: UniProt: P0DP29

-
Non-polymers , 4 types, 23 molecules

#3: Chemical ChemComp-K / POTASSIUM ION


Mass: 39.098 Da / Num. of mol.: 3 / Source method: obtained synthetically / Formula: K / Feature type: SUBJECT OF INVESTIGATION
#4: Chemical
ChemComp-A1B92 / N-(4,4-difluorocyclohexyl)-2-(3-methyl-1H-pyrazol-1-yl)-6-(morpholin-4-yl)pyrimidin-4-amine


Mass: 378.420 Da / Num. of mol.: 4 / Source method: obtained synthetically / Formula: C18H24F2N6O / Feature type: SUBJECT OF INVESTIGATION
#5: Chemical
ChemComp-CA / CALCIUM ION


Mass: 40.078 Da / Num. of mol.: 8 / Source method: obtained synthetically / Formula: Ca / Feature type: SUBJECT OF INVESTIGATION
#6: Water ChemComp-HOH / water


Mass: 18.015 Da / Num. of mol.: 8 / Source method: isolated from a natural source / Formula: H2O

-
Details

Has ligand of interestY
Has protein modificationY

-
Experimental details

-
Experiment

ExperimentMethod: ELECTRON MICROSCOPY
EM experimentAggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction

-
Sample preparation

ComponentName: RatKCa2.2_I/calmodulin channel in complex with rimtuzalcap
Type: COMPLEX / Entity ID: #1-#2 / Source: RECOMBINANT
Molecular weightValue: 0.22973 MDa / Experimental value: NO
Source (natural)Organism: Rattus norvegicus (Norway rat)
Source (recombinant)Organism: Homo sapiens (human) / Strain: HEK293s / Cell: HEK293 / Plasmid: pGEBacMam
Buffer solutionpH: 8
SpecimenConc.: 2 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES
VitrificationCryogen name: ETHANE

-
Electron microscopy imaging

Experimental equipment
Model: Titan Krios / Image courtesy: FEI Company
MicroscopyModel: TFS KRIOS
Electron gunElectron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM
Electron lensMode: BRIGHT FIELD / Nominal defocus max: 2300 nm / Nominal defocus min: 1300 nm
Specimen holderSpecimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER
Image recordingElectron dose: 50 e/Å2 / Film or detector model: FEI FALCON IV (4k x 4k)

-
Processing

EM software
IDNameVersionCategory
7Coot0.9.8.95 ELmodel fitting
9PHENIX1.21.1_5286model refinement
CTF correctionType: PHASE FLIPPING AND AMPLITUDE CORRECTION
3D reconstructionResolution: 3.13 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 64173 / Symmetry type: POINT
RefinementHighest resolution: 3.13 Å
Stereochemistry target values: REAL-SPACE (WEIGHTED MAP SUM AT ATOM CENTERS)
Refine LS restraints
Refine-IDTypeDev idealNumber
ELECTRON MICROSCOPYf_bond_d0.00316676
ELECTRON MICROSCOPYf_angle_d0.45922580
ELECTRON MICROSCOPYf_dihedral_angle_d5.382332
ELECTRON MICROSCOPYf_chiral_restr0.0372668
ELECTRON MICROSCOPYf_plane_restr0.0032808

+
About Yorodumi

-
News

-
Feb 9, 2022. New format data for meta-information of EMDB entries

New format data for meta-information of EMDB entries

  • Version 3 of the EMDB header file is now the official format.
  • The previous official version 1.9 will be removed from the archive.

Related info.:EMDB header

External links:wwPDB to switch to version 3 of the EMDB data model

-
Aug 12, 2020. Covid-19 info

Covid-19 info

URL: https://pdbj.org/emnavi/covid19.php

New page: Covid-19 featured information page in EM Navigator.

Related info.:Covid-19 info / Mar 5, 2020. Novel coronavirus structure data

+
Mar 5, 2020. Novel coronavirus structure data

Novel coronavirus structure data

Related info.:Yorodumi Speices / Aug 12, 2020. Covid-19 info

External links:COVID-19 featured content - PDBj / Molecule of the Month (242)：Coronavirus Proteases

+
Jan 31, 2019. EMDB accession codes are about to change! (news from PDBe EMDB page)

EMDB accession codes are about to change! (news from PDBe EMDB page)

  • The allocation of 4 digits for EMDB accession codes will soon come to an end. Whilst these codes will remain in use, new EMDB accession codes will include an additional digit and will expand incrementally as the available range of codes is exhausted. The current 4-digit format prefixed with “EMD-” (i.e. EMD-XXXX) will advance to a 5-digit format (i.e. EMD-XXXXX), and so on. It is currently estimated that the 4-digit codes will be depleted around Spring 2019, at which point the 5-digit format will come into force.
  • The EM Navigator/Yorodumi systems omit the EMD- prefix.

Related info.:Q: What is EMD? / ID/Accession-code notation in Yorodumi/EM Navigator

External links:EMDB Accession Codes are Changing Soon! / Contact to PDBj

+
Jul 12, 2017. Major update of PDB

Major update of PDB

  • wwPDB released updated PDB data conforming to the new PDBx/mmCIF dictionary.
  • This is a major update changing the version number from 4 to 5, and with Remediation, in which all the entries are updated.
  • In this update, many items about electron microscopy experimental information are reorganized (e.g. em_software).
  • Now, EM Navigator and Yorodumi are based on the updated data.

External links:wwPDB Remediation / Enriched Model Files Conforming to OneDep Data Standards Now Available in the PDB FTP Archive

-
Yorodumi

Thousand views of thousand structures

  • Yorodumi is a browser for structure data from EMDB, PDB, SASBDB, etc.
  • This page is also the successor to EM Navigator detail page, and also detail information page/front-end page for Omokage search.
  • The word "yorodu" (or yorozu) is an old Japanese word meaning "ten thousand". "mi" (miru) is to see.

Related info.:EMDB / PDB / SASBDB / Comparison of 3 databanks / Yorodumi Search / Aug 31, 2016. New EM Navigator & Yorodumi / Yorodumi Papers / Jmol/JSmol / Function and homology information / Changes in new EM Navigator and Yorodumi

Read more