6ux4

MthK N-terminal truncation RCK domain state 2 bound with calcium

Method: ELECTRON MICROSCOPY

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

Calcium-gated potassium channel MthK

Methanothermobacter thermautotrophicus

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 8	CALCIUM ION × 24 water × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	MTHK_METTH
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–336； UniProt 1–336 Author chain B； PDBConstruct 1–336； UniProt 1–336 Author chain C； PDBConstruct 1–336； UniProt 1–336 Author chain D； PDBConstruct 1–336； UniProt 1–336 Author chain E； PDBConstruct 1–336； UniProt 1–336 Author chain F； PDBConstruct 1–336； UniProt 1–336 Author chain G； PDBConstruct 1–336； UniProt 1–336 Author chain H； PDBConstruct 1–336； UniProt 1–336

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	6ux4
Deposition date deposition_date	2019-11-06
Structure title title	MthK N-terminal truncation RCK domain state 2 bound with calcium
Keywords keywords	MthK, TRANSPORT PROTEIN; TRANSPORT PROTEIN
Experimental Method method	ELECTRON MICROSCOPY

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3. Official assembly/model SAXS Official SAXS Profiles

This page reads only the latest assembly calculations. Every curve maps to an explicit PDB entry, official biological assembly and coordinate model.

6ux4__assembly_1__model_1

Assembly 1 · Model 1 · CRYSOL 4.1.3-1-20251215 (887e7ef)

Download this curve (.dat)

6ux4__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

6ux4__assembly_1__model_1 | P(r) · Pending

P(r) will be calculated and displayed separately for the same assembly/model.

Rg（Guinier）	43.11 Å
Rg (electron density)	43.05 Å
Total Rg	43.11 Å
Atom count	13232
Residues	1776
Excluded volume	236570 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`6ux4__assembly_1__model_1`	octameric （8）	Success	4.1.3-1-20251215 (887e7ef)	View Download

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4. Crystallography and Experiment 4. Crystallography & Experiment

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5. Entities and Polymers Entities & Polymers (3)

Entity 1 Entity 1 polymer

Description description	Calcium-gated potassium channel MthK
Molecular weight formula_weight	37356.2 kDa
Source method src_method	man
Copy count entity_count	8

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,E,B,F,C,G,D,H
Atom count atom_count	13257

MVLVIEIIRKHLPRVLKVPATRILLLVLAVIIYGTAGFHFIEGESWTVSLYWTFVTIATVGYGDYSPSTPLGMYFTVTLIVLGIGTFAVAVERLLEFLINREQMKLMGLIDVAKSRHVVICGWSESTLECLRELRGSEVFVLAEDENVRKKVLRSGANFVHGDPTRVSDLEKANVRGARAVIVDLESDSETIHCILGIRKIDESVRIIAEAERYENIEQLRMAGADQVISPFVISGRLMSRSIDDGYEAMFVQDVLAEESTRRMVEVPIPEGSKLEGVSVLDADIHDVTGVIIIGVGRGDELIIDPPRDYSFRAGDIILGIGKPEEIERLKNYISA

Source Source

Source organism organism	Methanothermobacter thermautotrophicus
NCBI taxonomy ID ncbi_taxonomy_id	145262
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 non-polymer

Description description	CALCIUM ION
Molecular weight formula_weight	40.1 kDa
Source method src_method	syn
Copy count entity_count	24

Entity 3 Entity 3 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	3

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6. Fold Classification (SCOP + CATH) 24 domains

CATH v4.4 (24 domains)

Domain ID domain_id	6ux4A01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	720 — NAD(P)-binding Rossmann-like Domain

Domain ID domain_id	6ux4A02
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	5 — Single alpha-helices involved in coiled-coils or other helix-helix interfaces
Homologous superfamily homologous superfamily	870 — Voltage-gated potassium channel

Domain ID domain_id	6ux4A03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily	1450 — Regulator of K+ conductance, C-terminal domain

Domain ID domain_id	6ux4B01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	720 — NAD(P)-binding Rossmann-like Domain

Domain ID domain_id	6ux4B02
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	5 — Single alpha-helices involved in coiled-coils or other helix-helix interfaces
Homologous superfamily homologous superfamily	870 — Voltage-gated potassium channel

Domain ID domain_id	6ux4B03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily	1450 — Regulator of K+ conductance, C-terminal domain

Domain ID domain_id	6ux4C01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	720 — NAD(P)-binding Rossmann-like Domain

Domain ID domain_id	6ux4C02
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	5 — Single alpha-helices involved in coiled-coils or other helix-helix interfaces
Homologous superfamily homologous superfamily	870 — Voltage-gated potassium channel

Domain ID domain_id	6ux4C03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily	1450 — Regulator of K+ conductance, C-terminal domain

Domain ID domain_id	6ux4D01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	720 — NAD(P)-binding Rossmann-like Domain

Domain ID domain_id	6ux4D02
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	5 — Single alpha-helices involved in coiled-coils or other helix-helix interfaces
Homologous superfamily homologous superfamily	870 — Voltage-gated potassium channel

Domain ID domain_id	6ux4D03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily	1450 — Regulator of K+ conductance, C-terminal domain

Domain ID domain_id	6ux4E01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	720 — NAD(P)-binding Rossmann-like Domain

Domain ID domain_id	6ux4E02
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	5 — Single alpha-helices involved in coiled-coils or other helix-helix interfaces
Homologous superfamily homologous superfamily	870 — Voltage-gated potassium channel

Domain ID domain_id	6ux4E03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily	1450 — Regulator of K+ conductance, C-terminal domain

Domain ID domain_id	6ux4F01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	720 — NAD(P)-binding Rossmann-like Domain

Domain ID domain_id	6ux4F02
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	5 — Single alpha-helices involved in coiled-coils or other helix-helix interfaces
Homologous superfamily homologous superfamily	870 — Voltage-gated potassium channel

Domain ID domain_id	6ux4F03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily	1450 — Regulator of K+ conductance, C-terminal domain

Domain ID domain_id	6ux4G01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	720 — NAD(P)-binding Rossmann-like Domain

Domain ID domain_id	6ux4G02
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	5 — Single alpha-helices involved in coiled-coils or other helix-helix interfaces
Homologous superfamily homologous superfamily	870 — Voltage-gated potassium channel

Domain ID domain_id	6ux4G03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily	1450 — Regulator of K+ conductance, C-terminal domain

Domain ID domain_id	6ux4H01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	720 — NAD(P)-binding Rossmann-like Domain

Domain ID domain_id	6ux4H02
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	5 — Single alpha-helices involved in coiled-coils or other helix-helix interfaces
Homologous superfamily homologous superfamily	870 — Voltage-gated potassium channel

Domain ID domain_id	6ux4H03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	70 — Alpha-Beta Plaits
Homologous superfamily homologous superfamily	1450 — Regulator of K+ conductance, C-terminal domain

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Unit-cell length a length_a	1.000 Å
Unit-cell length b length_b	1.000 Å
Unit-cell length c length_c	1.000 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	—

Space group space_group	P 1
Space-group number int_tables_number	1
Crystal system crystal_system	—

Resolution resolution	3.50 Å
Resolution测定Method resolution_method	—
颗粒数 num_particles	273492

MthK N-terminal truncation RCK domain state 2 bound with calcium

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

Calcium-gated potassium channel MthK

State in the Current Structure

Other States of the Same Protein in the Database

2. Structure Basics 2. Structure Basics

3. Official assembly/model SAXS Official SAXS Profiles

6ux4__assembly_1__model_1

6ux4__assembly_1__model_1 | I(q)

6ux4__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

冷冻电镜 EM 3D

5. Entities and Polymers Entities & Polymers (3)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 water

6. Fold Classification (SCOP + CATH) 24 domains

CATH v4.4 (24 domains)

7. Citations (1)

MthK N-terminal truncation RCK domain state 2 bound with calcium

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

Calcium-gated potassium channel MthK

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

2. Structure Basics 2. Structure Basics

3. Official assembly/model SAXS Official SAXS Profiles

6ux4__assembly_1__model_1

6ux4__assembly_1__model_1 | I(q)

6ux4__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

冷冻电镜 EM 3D

5. Entities and Polymers Entities & Polymers (3)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 water

6. Fold Classification (SCOP + CATH) 24 domains

CATH v4.4 (24 domains)

7. Citations (1)