SAXSdb — 1qs7

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

RS20

OrganismNot specified

UniProt P19038

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	CALMODULIN × 1 CALCIUM ION × 4 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 2	CALMODULIN × 1 CALCIUM ION × 4 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	KMLS_CHICK
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 1–19； UniProt 1731–1749 Author chain D； PDBConstruct 1–19； UniProt 1731–1749

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	1qs7
Deposition date deposition_date	1999-06-25
Structure title title	The 1.8 angstrom structure of calmodulin rs20 peptide complex
Keywords keywords	;CALMODULIN, CALCIUM BINDING, HELIX-LOOP-HELIX, SIGNALLING, COMPLEX(CALCIUM-BINDING PROTEIN-PEPTIDE), METAL BINDING PROTEIN-PEPTIDE COMPLEX ;; METAL BINDING PROTEIN/PEPTIDE
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.

1qs7__assembly_2__model_1

Assembly 2 · Model 1 · CRYSOL 4.1.3-1-20251215 (887e7ef)

Download this curve (.dat)

1qs7__assembly_2__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1qs7__assembly_2__model_1 | P(r) · Pending

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

Rg（Guinier）	16.84 Å
Rg (electron density)	15.54 Å
Total Rg	16.53 Å
Atom count	1274
Residues	161
Excluded volume	22420 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1qs7__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`1qs7__assembly_2__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	CALMODULIN
Molecular weight formula_weight	16328.0 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,C
Atom count atom_count	2859

LTDEQIAEFKEAFSLFDKDGDGTITTKELGTVMRSLGQNPTEAELQDMINEVDADGNGTIDFPEFLNLMARKMKDTDSEEELKEAFRVFDKDGNGFISAAELRHVMTNLGEKLTDEEVDEMIREADVDGDGQVNYEEFVQVMMAK

Source Source

Source organism organism	Escherichia coli
NCBI taxonomy ID ncbi_taxonomy_id	562
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 polymer

Description description	RS20
Molecular weight formula_weight	2327.7 kDa
Source method src_method	syn
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B,D

RRKWQKTGHAVRAIGRLSSSX

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	264

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6. Fold Classification (SCOP + CATH) 6 domains

SCOP 2.08 (2 domains)

Domain ID domain_id	d1qs7a_
Class class	k — Designed proteins
Fold Fold fold	k.21 — Calmodulin
Superfamily Superfamily superfamily	k.21.1 — Calmodulin
Family Family family	k.21.1.1 — Calmodulin

Domain ID domain_id	d1qs7c_
Class class	k — Designed proteins
Fold Fold fold	k.21 — Calmodulin
Superfamily Superfamily superfamily	k.21.1 — Calmodulin
Family Family family	k.21.1.1 — Calmodulin

CATH v4.4 (4 domains)

Domain ID domain_id	1qs7A01
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	1qs7A02
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	1qs7C01
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	1qs7C02
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	238 — Recoverin; domain 1
Homologous superfamily homologous superfamily	10 — EF-hand

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Unit-cell length a length_a	41.016 Å
Unit-cell length b length_b	54.481 Å
Unit-cell length c length_c	66.304 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	92.76 °
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	1.800 Å
Low-resolution limit resolution_low	28.870 Å
R factor r_factor	0.2280
R_work r_work	0.2280
R_free r_free	0.2590

The 1.8 angstrom structure of calmodulin rs20 peptide complex

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

RS20

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

1qs7__assembly_2__model_1

1qs7__assembly_2__model_1 | I(q)

1qs7__assembly_2__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

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

6. Fold Classification (SCOP + CATH) 6 domains

SCOP 2.08 (2 domains)

CATH v4.4 (4 domains)

7. Citations (3)

The 1.8 angstrom structure of calmodulin rs20 peptide complex

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

RS20

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

1qs7__assembly_2__model_1

1qs7__assembly_2__model_1 | I(q)

1qs7__assembly_2__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

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

6. Fold Classification (SCOP + CATH) 6 domains

SCOP 2.08 (2 domains)

CATH v4.4 (4 domains)

7. Citations (3)