SAXSdb — 8p81

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

Cyclin-dependent kinase 12

Homo sapiens

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	Cyclin-K × 1 （O75909） ~{N}-[[5,6-bis(chloranyl)-1~{H}-benzimidazol-2-yl]methyl]-9-(1-methylpyrazol-4-yl)-2-morpholin-4-yl-purin-6-amine × 1 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	CDK12_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 2–351； UniProt 714–1063

Cyclin-K

Homo sapiens

UniProt O75909

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	Cyclin-dependent kinase 12 × 1 （Q9NYV4） ~{N}-[[5,6-bis(chloranyl)-1~{H}-benzimidazol-2-yl]methyl]-9-(1-methylpyrazol-4-yl)-2-morpholin-4-yl-purin-6-amine × 1 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	CCNK_HUMAN
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 2–268； UniProt 1–267

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	8p81
Deposition date deposition_date	2023-05-31
Structure title title	Crystal structure of human Cdk12/Cyclin K in complex with inhibitor SR-4835
Keywords keywords	Cyclin-dependent kinase, inhibitor, SR-4835, Cdk12, Cyclin K, TRANSCRIPTION; TRANSCRIPTION
Experimental Method method	X-RAY DIFFRACTION

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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.

8p81__assembly_1__model_1

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

Download this curve (.dat)

8p81__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

8p81__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	28.35 Å
Rg (electron density)	27.43 Å
Total Rg	28.22 Å
Atom count	4538
Residues	558
Excluded volume	81208 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`8p81__assembly_1__model_1`	dimeric （2）	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 (4)

Entity 1 Entity 1 polymer

Description description	Cyclin-dependent kinase 12
Molecular weight formula_weight	40765.0 kDa
EC 编号 ec_number	2.7.11.22,2.7.11.23
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A
Atom count atom_count	4568

GQTESDWGKRCVDKFDIIGIIGEGTYGQVYKAKDKDTGELVALKKVRLDNEKEGFPITAIREIKILRQLIHRSVVNMKEIVTDKQDALDFKKDKGAFYLVFEYMDHDLMGLLESGLVHFSEDHIKSFMKQLMEGLEYCHKKNFLHRDIKCSNILLNNSGQIKLADFGLARLYNSEESRPYTNKVITLWYRPPELLLGEERYTPAIDVWSCGCILGELFTKKPIFQANLELAQLELISRLCGSPCPAVWPDVIKLPYFNTMKPKKQYRRRLREEFSFIPSAALDLLDHMLTLDPSKRCTAEQTLQSDFLKDVELSKMAPPDLPHWQDCHELWSKKRRRQRQSGVVVEEPPPS

Source Source

Source organism organism	Homo sapiens
Common name common_name	human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Spodoptera frugiperda

Entity 2 Entity 2 polymer

Description description	Cyclin-K
Molecular weight formula_weight	31429.2 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B

GMKENKENSSPSVTSANLDHTKPCWYWDKKDLAHTPSQLEGLDPATEARYRREGARFIFDVGTRLGLHYDTLATGIIYFHRFYMFHSFKQFPRYVTGACCLFLAGKVEETPKKCKDIIKTARSLLNDVQFGQFGDDPKEEVMVLERILLQTIKFDLQVEHPYQFLLKYAKQLKGDKNKIQKLVQMAWTFVNDSLCTTLSLQWEPEIIAVAVMYLAGRLCKFEIQEWTSKPMYRRWWEQFVQDVPVDVLEDICHQILDLYSQGKQQMPH

Source Source

Source organism organism	Homo sapiens
Common name common_name	human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Spodoptera frugiperda

Entity 3 Entity 3 non-polymer

Description description	~{N}-[[5,6-bis(chloranyl)-1~{H}-benzimidazol-2-yl]methyl]-9-(1-methylpyrazol-4-yl)-2-morpholin-4-yl-purin-6-amine
Molecular weight formula_weight	499.4 kDa
Source method src_method	nat
Copy count entity_count	1

Entity 4 Entity 4 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	24

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Unit-cell length a length_a	103.042 Å
Unit-cell length b length_b	137.906 Å
Unit-cell length c length_c	58.471 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	4

Space group space_group	P 21 21 2
Space-group number int_tables_number	18
Crystal system crystal_system	—

Resolution resolution	2.680 Å
Low-resolution limit resolution_low	57.310 Å
R factor r_factor	0.2116
R_work r_work	0.2070
R_free r_free	0.2548

Crystal structure of human Cdk12/Cyclin K in complex with inhibitor SR-4835

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

Cyclin-dependent kinase 12

State in the Current Structure

Other States of the Same Protein in the Database

Cyclin-K

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

8p81__assembly_1__model_1

8p81__assembly_1__model_1 | I(q)

8p81__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

Diffraction experiment Diffraction

5. Entities and Polymers Entities & Polymers (4)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

7. Citations (1)

Crystal structure of human Cdk12/Cyclin K in complex with inhibitor SR-4835

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

Cyclin-dependent kinase 12

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Cyclin-K

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

8p81__assembly_1__model_1

8p81__assembly_1__model_1 | I(q)

8p81__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

Diffraction experiment Diffraction

5. Entities and Polymers Entities & Polymers (4)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

7. Citations (1)