6kn8

Structure of human cardiac thin filament in the calcium bound state

Method: ELECTRON MICROSCOPY

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

Actin, alpha skeletal muscle

OrganismNot specified

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 29	Tropomyosin alpha-1 chain × 4 （P09493） Tropomyosin alpha-1 chain × 4 （P09493） Troponin T, cardiac muscle × 2 （P45379） Troponin I, cardiac muscle × 2 （P19429） Troponin C, slow skeletal and cardiac muscles × 2 （P63316） ADENOSINE-5'-DIPHOSPHATE × 15	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	ACTS_RABIT
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–375； UniProt 3–377 Author chain B； PDBConstruct 1–375； UniProt 3–377 Author chain C； PDBConstruct 1–375； UniProt 3–377 Author chain D； PDBConstruct 1–375； UniProt 3–377 Author chain E； PDBConstruct 1–375； UniProt 3–377 Author chain F； PDBConstruct 1–375； UniProt 3–377 Author chain G； PDBConstruct 1–375； UniProt 3–377 Author chain H； PDBConstruct 1–375； UniProt 3–377 Author chain I； PDBConstruct 1–375； UniProt 3–377 Author chain J； PDBConstruct 1–375； UniProt 3–377 Author chain K； PDBConstruct 1–375； UniProt 3–377 Author chain L； PDBConstruct 1–375； UniProt 3–377 Author chain M； PDBConstruct 1–375； UniProt 3–377 Author chain N； PDBConstruct 1–375； UniProt 3–377 Author chain O； PDBConstruct 1–375； UniProt 3–377

Tropomyosin alpha-1 chain

Homo sapiens

UniProt P09493

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 29	Actin, alpha skeletal muscle × 15 （P68135） Troponin T, cardiac muscle × 2 （P45379） Troponin I, cardiac muscle × 2 （P19429） Troponin C, slow skeletal and cardiac muscles × 2 （P63316） ADENOSINE-5'-DIPHOSPHATE × 15	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	TPM1_HUMAN
Isoform	—
PDB entities	2, 3
Chains and sequence ranges	Author chain P； PDBConstruct 1–274； UniProt 11–284 Author chain Q； PDBConstruct 1–274； UniProt 11–284 Author chain W； PDBConstruct 1–274； UniProt 11–284 Author chain X； PDBConstruct 1–274； UniProt 11–284 Author chain R； PDBConstruct 3–31； UniProt 1–29 Author chain S； PDBConstruct 3–31； UniProt 1–29 Author chain Y； PDBConstruct 3–31； UniProt 1–29 Author chain Z； PDBConstruct 3–31； UniProt 1–29

Troponin T, cardiac muscle

Homo sapiens

UniProt P45379

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 29	Actin, alpha skeletal muscle × 15 （P68135） Tropomyosin alpha-1 chain × 4 （P09493） Tropomyosin alpha-1 chain × 4 （P09493） Troponin I, cardiac muscle × 2 （P19429） Troponin C, slow skeletal and cardiac muscles × 2 （P63316） ADENOSINE-5'-DIPHOSPHATE × 15	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	TNNT2_HUMAN
Isoform	P45379-6
PDB entities	4
Chains and sequence ranges	Author chain T； PDBConstruct 1–174； UniProt 99–272 Author chain a； PDBConstruct 1–174； UniProt 99–272

Troponin I, cardiac muscle

Homo sapiens

UniProt P19429

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 29	Actin, alpha skeletal muscle × 15 （P68135） Tropomyosin alpha-1 chain × 4 （P09493） Tropomyosin alpha-1 chain × 4 （P09493） Troponin T, cardiac muscle × 2 （P45379） Troponin C, slow skeletal and cardiac muscles × 2 （P63316） ADENOSINE-5'-DIPHOSPHATE × 15	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	TNNI3_HUMAN
Isoform	—
PDB entities	5
Chains and sequence ranges	Author chain U； PDBConstruct 1–126； UniProt 41–166 Author chain b； PDBConstruct 1–126； UniProt 41–166

Troponin C, slow skeletal and cardiac muscles

Homo sapiens

UniProt P63316

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 29	Actin, alpha skeletal muscle × 15 （P68135） Tropomyosin alpha-1 chain × 4 （P09493） Tropomyosin alpha-1 chain × 4 （P09493） Troponin T, cardiac muscle × 2 （P45379） Troponin I, cardiac muscle × 2 （P19429） ADENOSINE-5'-DIPHOSPHATE × 15	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	TNNC1_HUMAN
Isoform	—
PDB entities	6
Chains and sequence ranges	Author chain V； PDBConstruct 1–160； UniProt 2–161 Author chain c； PDBConstruct 1–160； UniProt 2–161

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	6kn8
Deposition date deposition_date	2019-08-03
Structure title title	Structure of human cardiac thin filament in the calcium bound state
Keywords keywords	Troponin, Tropomyosin, Actin, Thin filement, Muscle, CONTRACTILE PROTEIN-ACTIN BINDING PROTEIN complex; CONTRACTILE PROTEIN/ACTIN BINDING 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.

6kn8__assembly_1__model_1

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

Download this curve (.dat)

6kn8__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

6kn8__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	0.00 Å
Rg (electron density)	117.40 Å
Total Rg	117.00 Å
Atom count	60966
Residues	7669
Excluded volume	1081300 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`6kn8__assembly_1__model_1`	29-meric （29）	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 (7)

Entity 1 Entity 1 polymer

Description description	Actin, alpha skeletal muscle
Molecular weight formula_weight	41862.6 kDa
Source method src_method	nat
Copy count entity_count	15

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,C,D,E,F,G,H,I,J,K,L,M,N,O
Atom count atom_count	60966

DEDETTALVCDNGSGLVKAGFAGDDAPRAVFPSIVGRPRHQGVMVGMGQKDSYVGDEAQSKRGILTLKYPIEHGIITNWDDMEKIWHHTFYNELRVAPEEHPTLLTEAPLNPKANREKMTQIMFETFNVPAMYVAIQAVLSLYASGRTTGIVLDSGDGVTHNVPIYEGYALPHAIMRLDLAGRDLTDYLMKILTERGYSFVTTAEREIVRDIKEKLCYVALDFENEMATAASSSSLEKSYELPDGQVITIGNERFRCPETLFQPSFIGMESAGIHETTYNSIMKCDIDIRKDLYANNVMSGGTTMYPGIADRMQKEITALAPSTMKIKIIAPPERKYSVWIGGSILASLSTFQQMWITKQEYDEAGPSIVHRKCF

Entity 2 Entity 2 polymer

Description description	Tropomyosin alpha-1 chain
Molecular weight formula_weight	31555.1 kDa
Source method src_method	man
Copy count entity_count	4

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	P,Q,W,X

LKLDKENALDRAEQAEADKKAAEDRSKQLEDELVSLQKKLKGTEDELDKYSEALKDAQEKLELAEKKATDAEADVASLNRRIQLVEEELDRAQERLATALQKLEEAEKAADESERGMKVIESRAQKDEEKMEIQEIQLKEAKHIAEDADRKYEEVARKLVIIESDLERAEERAELSEGKCAELEEELKTVTNNLKSLEAQAEKYSQKEDRYEEEIKVLSDKLKEAETRAEFAERSVTKLEKSIDDLEDELYAQKLKYKAISEELDHALNDMTSI

Source Source

Source organism organism	Homo sapiens
Common name common_name	Human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Escherichia coli

Entity 3 Entity 3 polymer

Description description	Tropomyosin alpha-1 chain
Molecular weight formula_weight	3528.1 kDa
Source method src_method	man
Copy count entity_count	4

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	R,S,Y,Z

ASMDAIKKKMQMLKLDKENALDRAEQAEADK

Source Source

Source organism organism	Homo sapiens
Common name common_name	Human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Escherichia coli

Entity 4 Entity 4 polymer

Description description	Troponin T, cardiac muscle
Molecular weight formula_weight	21446.2 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	T,a

LNELQALIEAHFENRKKEEEELVSLKDRIERRRAERAEQQRIRNEREKERQNRLAEERARREEEENRRKAEDEARKKKALSNMMHFGGYIQKQAQTERKSGKRQTEREKKKKILAERRKVLAIDHLNEDQLREKAKELWQSIYNLEAEKFDLQEKFKQQKYEINVLRNRINDNQ

Source Source

Source organism organism	Homo sapiens
Common name common_name	Human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Escherichia coli

Entity 5 Entity 5 polymer

Description description	Troponin I, cardiac muscle
Molecular weight formula_weight	14430.8 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	U,b

ISASRKLQLKTLLLQIAKQELEREAEERRGEKGRALSTRCQPLELAGLGFAELQDLCRQLHARVDKVDEERYDIEAKVTKNITEIADLTQKIFDLRGKFKRPTLRRVRISADAMMQALLGARAKES

Source Source

Source organism organism	Homo sapiens
Common name common_name	Human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Escherichia coli

Entity 6 Entity 6 polymer

Description description	Troponin C, slow skeletal and cardiac muscles
Molecular weight formula_weight	18288.3 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	V,c

DDIYKAAVEQLTEEQKNEFKAAFDIFVLGAEDGCISTKELGKVMRMLGQNPTPEELQEMIDEVDEDGSGTVDFDEFLVMMVRCMKDDSKGKSEEELSDLFRMFDKNADGYIDLDELKIMLQATGETITEDDIEELMKDGDKNNDGRIDYDEFLEFMKGVE

Source Source

Source organism organism	Homo sapiens
Common name common_name	Human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Escherichia coli

Entity 7 Entity 7 non-polymer

Description description	ADENOSINE-5'-DIPHOSPHATE
Molecular weight formula_weight	427.2 kDa
Source method src_method	syn
Copy count entity_count	15

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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	4.80 Å
Resolution测定Method resolution_method	—
颗粒数 num_particles	23374

Structure of human cardiac thin filament in the calcium bound state

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

Actin, alpha skeletal muscle

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Tropomyosin alpha-1 chain

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Troponin T, cardiac muscle

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Troponin I, cardiac muscle

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Troponin C, slow skeletal and cardiac muscles

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

6kn8__assembly_1__model_1

6kn8__assembly_1__model_1 | I(q)

6kn8__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 (7)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 polymer

Polymer Polymer

Source Source

Entity 4 Entity 4 polymer

Polymer Polymer

Source Source

Entity 5 Entity 5 polymer

Polymer Polymer

Source Source

Entity 6 Entity 6 polymer

Polymer Polymer

Source Source

Entity 7 Entity 7 non-polymer

7. Citations (1)