SAXSdb — 6d42

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1. Protein Identity and Related Structures Protein Identity & Related Structures

Intermediate conductance calcium-activated potassium channel protein 4

Homo sapiens

State in the Current Structure

Assembly	Oligomeric State	Construct	Mutations and Modifications	Ligands, Ions and Associated Components	Method and Experimental Conditions	Structure Quality
1	Protein homooligomer Homooligomer Protein × 4 PDB declaration: tetrameric（4） Consistent with protein copy count	Chain A； UniProt 376–415	Non-standard monomer：Yes (specific site not provided by mmCIF)	CU COPPER (II) ION × 4	X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, HANGING DROP；pH 6.5；290 K；0.1 M imidazole, pH 6.5 1.0 M sodium acetate	Resolution 1.75 Å R-free 0.323
2	Protein homooligomer Homooligomer Protein × 4 PDB declaration: tetrameric（4） Consistent with protein copy count	Chain B； UniProt 376–415	Non-standard monomer：Yes (specific site not provided by mmCIF)	CU COPPER (II) ION × 4	X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, HANGING DROP；pH 6.5；290 K；0.1 M imidazole, pH 6.5 1.0 M sodium acetate	Resolution 1.75 Å R-free 0.323

Other States of the Same Protein in the Database

Each row is a biological assembly of the same UniProt protein in another PDB entry. The “Difference from current entry” column identifies evidence-level differences; no tag means the currently parsed fields agree.

Other PDB	Difference from Current Entry 6D42	Assembly / Oligomeric State	Construct	Mutations and Modifications	Ligands, Ions and Non-polymers	Method and Experimental Conditions	Structure Quality
6CNM Cryo-EM structure of the human SK4/calmodulin channel complex Deposited 2018-03-08	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 1–427（427 aa） Chain B 1–427（427 aa） Chain C 1–427（427 aa） Chain D 1–427（427 aa）	Not recorded	K POTASSIUM ION × 5 POV (2S)-3-(hexadecanoyloxy)-2-[(9Z)-octadec-9-enoyloxy]propyl 2-(trimethylammonio)ethyl phosphate × 4 LMT DODECYL-BETA-D-MALTOSIDE × 8	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.40 Å
6CNN Cryo-EM structure of the human SK4/calmodulin channel complex in the Ca2+ bound state I Deposited 2018-03-08	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 1–427（427 aa） Chain B 1–427（427 aa） Chain C 1–427（427 aa） Chain D 1–427（427 aa）	Not recorded	K POTASSIUM ION × 4 POV (2S)-3-(hexadecanoyloxy)-2-[(9Z)-octadec-9-enoyloxy]propyl 2-(trimethylammonio)ethyl phosphate × 4 LMT DODECYL-BETA-D-MALTOSIDE × 8 CA CALCIUM ION × 12	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.50 Å
6CNO Cryo-EM structure of the human SK4/calmodulin channel complex in the Ca2+ bound state II Deposited 2018-03-08	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 1–427（427 aa） Chain B 1–427（427 aa） Chain C 1–427（427 aa） Chain D 1–427（427 aa）	Not recorded	CA CALCIUM ION × 12	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 4.70 Å
9ED1 Cryo-EM structure of the human KCa3.1/calmodulin channel in complex with Ca2+ and 1,4-dihydropyridine (DHP-103) Deposited 2024-11-15	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 9–386（378 aa） Chain B 9–386（378 aa） Chain C 9–386（378 aa） Chain D 9–386（378 aa）	Not recorded	K POTASSIUM ION × 5 CA CALCIUM ION × 12	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.50 Å
9O48 Cryo-EM structure of the human SK2-4 chimera/calmodulin channel complex in the Ca2+ bound state Deposited 2025-04-08	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Insufficient information Heteromer；Protein × 8 PDB declaration: octameric	Chain A 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain A 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain B 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain B 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain C 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain C 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain D 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain D 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428	Not recorded	K POTASSIUM ION × 2 CA CALCIUM ION × 16	ELECTRON MICROSCOPY cryo-EM buffer pH 8；20 mM Tris pH 8, 150 mM KCl, 2 mM CaCl2, 0.005% GDN, 0.0005% CHS cryo-EM vitrification conditions Cryogen ETHANE；5 uL of sample was applied to grids at 4 degree temperature with 100% humidity. After 30 seconds, grids were blotted for 5 seconds with blot force 25 and plunged into liquid ethane.	Resolution 3.10 Å
9O51 Cryo-EM structure of the human SK2-4 chimera/calmodulin channel complex in the Ca2+ free state Deposited 2025-04-09	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Insufficient information Heteromer；Protein × 8 PDB declaration: octameric	Chain A 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain A 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain B 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain B 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain C 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain C 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain D 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain D 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428	Not recorded	K POTASSIUM ION × 2 CA CALCIUM ION × 4	ELECTRON MICROSCOPY cryo-EM buffer pH 8；20 mM Tris pH 8, 150 mM KCl, 5 mM EGTA, 0.005% GDN, 0.0005% CHS cryo-EM vitrification conditions Cryogen ETHANE；5 uL of sample was applied to grids at 4 degree temperature with 100% humidity. After 30 seconds, grids were blotted for 5 seconds with blot force 25 and plunged into liquid ethane.	Resolution 3.40 Å
9O52 Cryo-EM structure of the human SK2-4 chimera/calmodulin channel complex bound to the bee toxin apamin Deposited 2025-04-09	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Insufficient information Heteromer；Protein × 9 PDB declaration: nonameric	Chain A 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain A 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain B 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain B 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain C 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain C 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain D 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain D 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428	Not recorded	K POTASSIUM ION × 4 CA CALCIUM ION × 16	ELECTRON MICROSCOPY cryo-EM buffer pH 8；20 mM Tris pH 8, 150 mM KCl, 2 mM CaCl2, 0.005% GDN, 0.0005% CHS cryo-EM vitrification conditions Cryogen ETHANE；5 uL of sample was applied to grids at 4 degree temperature with 100% humidity. After 30 seconds, grids were blotted for 5 seconds with blot force 25 and plunged into liquid ethane.	Resolution 3.18 Å
9O53 Cryo-EM structure of the human SK2-4 chimera/calmodulin channel complex bound to a small molecule inhibitor Deposited 2025-04-09	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Insufficient information Heteromer；Protein × 8 PDB declaration: octameric	Chain A 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain A 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain B 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain B 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain C 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain C 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain D 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain D 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428	Not recorded	A1B8D N-(2,1,3-benzoxadiazol-4-yl)-3-(4-methoxybenzene-1-sulfonamido)benzamide × 4 K POTASSIUM ION × 4 CA CALCIUM ION × 16	ELECTRON MICROSCOPY cryo-EM buffer pH 8；20 mM Tris pH 8, 150 mM KCl, 2 mM CaCl2, 0.005% GDN, 0.0005% CHS cryo-EM vitrification conditions Cryogen ETHANE；5 uL of sample was applied to grids at 4 degree temperature with 100% humidity. After 30 seconds, grids were blotted for 5 seconds with blot force 25 and plunged into liquid ethane.	Resolution 3.30 Å
9O5O Cryo-EM structure of the human SK2-4 chimera/calmodulin channel complex bound to a small molecule activator Deposited 2025-04-10	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Insufficient information Heteromer；Protein × 8 PDB declaration: octameric	Chain A 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain A 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain B 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain B 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain C 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain C 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain D 1–14（14 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428 Chain D 305–427（123 aa） Fragment：SK4 residues 1-15 + SK2 residues 124-412 + SK4 residues 306-428	Not recorded	A1B8G N-(2,1,3-benzoxadiazol-4-yl)-4-(trifluoromethyl)benzamide × 4 K POTASSIUM ION × 2 CA CALCIUM ION × 16	ELECTRON MICROSCOPY cryo-EM buffer pH 8；20 mM Tris pH 8, 150 mM KCl, 2 mM CaCl2, 0.005% GDN, 0.0005% CHS cryo-EM vitrification conditions Cryogen ETHANE；5 uL of sample was applied to grids at 4 degree temperature with 100% humidity. After 30 seconds, grids were blotted for 5 seconds with blot force 25 and plunged into liquid ethane.	Resolution 3.10 Å
9OA8 Cryo-EM structure of KCa3.1/calmodulin channel in complex with NS309 Deposited 2025-04-19	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 9–386（378 aa） Chain B 9–386（378 aa） Chain C 9–386（378 aa） Chain D 9–386（378 aa）	Not recorded	K POTASSIUM ION × 3 1KP (3E)-6,7-dichloro-3-(hydroxyimino)-1,3-dihydro-2H-indol-2-one × 4 CA CALCIUM ION × 8	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.59 Å
9Y5Q Cryo EM structure of KCa3.1_R355K_I/calmodulin channel in complex with rimtuzalcap Deposited 2025-09-05	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 9–386（378 aa） Chain B 9–386（378 aa） Chain C 9–386（378 aa） Chain D 9–386（378 aa）	Mutation：R355K Mutation：R355K Mutation：R355K Mutation：R355K	K POTASSIUM ION × 1 A1B92 Rimtuzalcap × 4 CA CALCIUM ION × 4	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 4.73 Å
9YDZ Cryo EM structure of KCa3.1_R355K_II/calmodulin channel in complex with rimtuzalcap Deposited 2025-09-23	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 9–366（358 aa） Chain B 9–366（358 aa） Chain C 9–366（358 aa） Chain D 9–366（358 aa）	Mutation：R355K Mutation：R355K Mutation：R355K Mutation：R355K	K POTASSIUM ION × 4	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.40 Å
9ZPO Cryo-EM structure of KCa3.1_I/calmodulin channel in complex with SKA31. Deposited 2025-12-16	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 9–386（378 aa） Chain B 9–386（378 aa） Chain C 9–386（378 aa） Chain D 9–386（378 aa）	Not recorded	A1C3Q naphtho[1,2-d][1,3]thiazol-2-amine × 4 CA CALCIUM ION × 8	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.67 Å
9ZPT Cryo-EM structure of KCa3.1_II/calmodulin channel in complex with SKA31. Deposited 2025-12-17	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 9–366（358 aa） Chain B 9–366（358 aa） Chain C 9–366（358 aa） Chain D 9–366（358 aa）	Not recorded	K POTASSIUM ION × 4	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.39 Å
9ZRK Cryo-EM structure of KCa3.1_I/calmodulin channel in complex with SKA111. Deposited 2025-12-20	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 9–386（378 aa） Chain B 9–386（378 aa） Chain C 9–386（378 aa） Chain D 9–386（378 aa）	Not recorded	A1C3U 5-methylnaphtho[1,2-d][1,3]thiazol-2-amine × 4 K POTASSIUM ION × 4 CA CALCIUM ION × 16	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 2.99 Å
9ZRL Cryo-EM structure of KCa3.1_II/calmodulin channel in complex with SKA111. Deposited 2025-12-20	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric	Chain A 9–369（361 aa） Chain B 9–369（361 aa） Chain C 9–369（361 aa） Chain D 9–369（361 aa）	Not recorded	K POTASSIUM ION × 4	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.38 Å

16 other PDB entries and 16 assemblies. Open the comparison page and filter oligomeric states

View Construct and Data Evidence

UniProt name	KCNN4_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 3–42； UniProt 376–415 Author chain B； PDBConstruct 3–42； UniProt 376–415

The page prioritizes protein identity, the current assembly, associated components, oligomeric state and cross-PDB links. Chain mapping and sequence ranges are retained as data evidence. Internal IDs, import timestamps and assembly operation expressions are maintenance fields and are not shown here.

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2. Structure Basics 2. Structure Basics

Entry ID entry_id	6d42
Deposition date deposition_date	2018-04-17
Structure title title	Crystal structure of the KCa3.1 C-terminal four-helix bundle (with copper)
Keywords keywords	Four-helix bundle, copper, MEMBRANE PROTEIN; MEMBRANE PROTEIN
Experimental Method method	X-RAY DIFFRACTION

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3. SAXS Parameters (CRYSOL theoretical calculation) 3. SAXS Parameters (CRYSOL)

Radius of gyration Rg (Guinier) rg_guinier	22.74 Å
Radius of gyration Rg (electron density) rg_electron	23.42 Å
Forward intensity I(0) i0	1634020.00
Molecular weight molecular_weight	8754.0 kDa
Excluded volume excluded_volume	10855 Å³
Envelope volume envelope_volume	16025 Å³
Hydration-shell volume shell_volume	7582 Å³
Envelope diameter envelope_diameter	86.3 Å
Shell Rg shell_rg	23.99 Å
Envelope Rg envelope_rg	23.64 Å
Shape Rg shape_rg	23.12 Å
Total Rg total_rg	24.36 Å
Total atoms total_atoms	600
Residues n_residues	76
Spherical-harmonic order n_harmonics	20
q range q_range	— – 0.5000 Å⁻¹
Data points n_points	101
Shell type shell_type	directional
Solvent electron density solvent_density	0.3340 e/Å³
Shell contrast contrast_shell	0.0300 e/Å³
CRYSOL version crysol_version	4.1.3

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4. P(r) Distance Distribution (GNOM inversion) 4. P(r) Analysis (GNOM)

Maximum dimension Dmax dmax	88.4 Å
Rg (real space) rg_real	23.35 Å
Rg uncertainty (real space) rg_real_error	1.25 Å
I(0) (real space) i0_real	1.6340e+06
I(0) uncertainty (real space) i0_real_error	2.5250e+04
Rg (reciprocal space) rg_reciprocal	23.20 Å
I(0) (reciprocal space) i0_reciprocal	1634000.0000
Solution quality estimate total_estimate	0.6905
Solution quality rating solution_quality	REASONABLE a REASONABLE solution
P(r) peaks n_peaks	1
Primary peak position r_peak_primary	87.0 Å
Skewness Skewness skewness	0.703
Kurtosis Kurtosis kurtosis	-0.060
Angular range angular_range	— – 0.3500 Å⁻¹
Current regularization parameter α current_alpha	0.0000
Highest regularization parameter α highest_alpha	63870.0000
Real-space data points n_real_points	67
GNOM version gnom_version	4.1.3
Quality Criteria quality_criteria	AN1: 0.000; Oscil: 0.322; Stabil: 1.000; Sysdev: 1.000; Positv: 1.000; Valcen: 0.087; Smooth: 0.920

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5. Crystallography and Experiment 5. Crystallography & Experiment

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6. Entities and Polymers Entities & Polymers (3)

Entity 1 Entity 1 polymer

Description description	Intermediate conductance calcium-activated potassium channel protein 4
Molecular weight formula_weight	4567.0 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B
Atom count atom_count	642

GSMILYDLQQNLSSSHRALEKQIDTLAGKLDALTELLSTALG

来源 Source

来源生物 organism	Homo sapiens
通用名 common_name	Human
NCBI Class编号 ncbi_taxonomy_id	9606
宿主生物 host_organism	Escherichia coli

Entity 2 Entity 2 non-polymer

Description description	COPPER (II) ION
Molecular weight formula_weight	63.5 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 3 Entity 3 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	42

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8. Citations (1)

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Unit-cell length a length_a	37.590 Å
Unit-cell length b length_b	37.590 Å
Unit-cell length c length_c	116.946 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.00 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	16

Space group space_group	P 4 21 2
Space-group number int_tables_number	90
Crystal system crystal_system	tetragonal

Resolution resolution	1.750 Å
Low-resolution limit resolution_low	27.059 Å
R factor r_factor	0.2595
R_work r_work	0.2521
R_free r_free	0.3226

fit	/app/data/saxs_computation/d4/6d42/6d42.fit
pddf	/app/data/pr_computation/d4/6d42/6d42.pr.out
profile	/app/data/saxs_computation/d4/6d42/6d42.dat

Crystal structure of the KCa3.1 C-terminal four-helix bundle (with copper)

1. Protein Identity and Related Structures Protein Identity & Related Structures

Intermediate conductance calcium-activated potassium channel protein 4

State in the Current Structure

Other States of the Same Protein in the Database

SAXS scattering curve SAXS Profile

P(r) Distance Distribution P(r) Distribution

2. Structure Basics 2. Structure Basics

3. SAXS Parameters (CRYSOL theoretical calculation) 3. SAXS Parameters (CRYSOL)

4. P(r) Distance Distribution (GNOM inversion) 4. P(r) Analysis (GNOM)

5. Crystallography and Experiment 5. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

Diffraction experiment Diffraction