SAXSdb — 4phk

▼

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

Calpain small subunit 1

Homo sapiens

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 2	(Z)-3-(4-chlorophenyl)-2-mercaptoacrylic acid × 2 CALCIUM ION × 8 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	CPNS1_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–173； UniProt 96–268 Author chain B； PDBConstruct 1–173； UniProt 96–268

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.

▼

2. Structure Basics 2. Structure Basics

Entry ID entry_id	4phk
Deposition date deposition_date	2014-05-06
Structure title title	The Structural Basis of Differential Inhibition of Human Calpain by Indole and Phenyl alpha-Mercaptoacrylic Acids. The complex with (Z)-3-(4-chlorophenyl)-2-mercaptoacrylic acid
Keywords keywords	Domain VI, PEF(S), Calcium Binding, Protease, hydrolase; HYDROLASE
Experimental Method method	X-RAY DIFFRACTION

▼

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.

4phk__assembly_1__model_1

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

Download this curve (.dat)

4phk__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

4phk__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	21.67 Å
Rg (electron density)	20.55 Å
Total Rg	21.34 Å
Atom count	2840
Residues	346
Excluded volume	50458 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`4phk__assembly_1__model_1`	Dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download

▶

4. Crystallography and Experiment 4. Crystallography & Experiment

▶

5. Entities and Polymers Entities & Polymers (4)

Entity 1 Entity 1 polymer

Description description	Calpain small subunit 1
Molecular weight formula_weight	20016.6 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	2991

EEVRQFRRLFAQLAGDDMEVSATELMNILNKVVTRHPDLKTDGFGIDTCRSMVAVMDSDTTGKLGFEEFKYLWNNIKRWQAIYKQFDTDRSGTICSSELPGAFEAAGFHLNEHLYNMIIRRYSDESGNMDFDNFISCLVRLDAMFRAFKSLDKDGTGQIQVNIQEWLQLTMYS

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 2 Entity 2 non-polymer

Description description	(Z)-3-(4-chlorophenyl)-2-mercaptoacrylic acid
Molecular weight formula_weight	214.7 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 3 Entity 3 non-polymer

Description description	CALCIUM ION
Molecular weight formula_weight	40.1 kDa
Source method src_method	syn
Copy count entity_count	8

Entity 4 Entity 4 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	140

▼

6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

Domain ID domain_id	d4phka_
Class class	a — All alpha proteins
Fold Fold fold	a.39 — EF Hand-like
Superfamily Superfamily superfamily	a.39.1 — EF-hand
Family Family family	a.39.1.8 — Penta-EF-hand proteins

Domain ID domain_id	d4phkb_
Class class	a — All alpha proteins
Fold Fold fold	a.39 — EF Hand-like
Superfamily Superfamily superfamily	a.39.1 — EF-hand
Family Family family	a.39.1.8 — Penta-EF-hand proteins

CATH v4.4 (2 domains)

Domain ID domain_id	4phkA00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	238 — Recoverin; domain 1
Homologous superfamily homologous superfamily	10 — EF-hand

Domain ID domain_id	4phkB00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	238 — Recoverin; domain 1
Homologous superfamily homologous superfamily	10 — EF-hand

▶

Unit-cell length a length_a	49.540 Å
Unit-cell length b length_b	80.090 Å
Unit-cell length c length_c	56.890 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	91.33 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	4

Space group space_group	P 1 21 1
Space-group number int_tables_number	4
Crystal system crystal_system	—

Resolution resolution	2.050 Å
Low-resolution limit resolution_low	80.090 Å
R factor r_factor	0.2333
R_work r_work	0.2307
R_free r_free	0.2794

The Structural Basis of Differential Inhibition of Human Calpain by Indole and Phenyl alpha-Mercaptoacrylic Acids. The complex with (Z)-3-(4-chlorophenyl)-2-mercaptoacrylic acid

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

Calpain small subunit 1

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

4phk__assembly_1__model_1

4phk__assembly_1__model_1 | I(q)

4phk__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 non-polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)

The Structural Basis of Differential Inhibition of Human Calpain by Indole and Phenyl alpha-Mercaptoacrylic Acids. The complex with (Z)-3-(4-chlorophenyl)-2-mercaptoacrylic acid

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

Calpain small subunit 1

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

4phk__assembly_1__model_1

4phk__assembly_1__model_1 | I(q)

4phk__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 non-polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)