SAXSdb — 1qu7

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

METHYL-ACCEPTING CHEMOTAXIS PROTEIN I

Escherichia coli

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 2	water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	MCP1_ECOLI
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–227； UniProt 294–520 Author chain B； PDBConstruct 1–227； UniProt 294–520

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	1qu7
Deposition date deposition_date	1999-07-07
Structure title title	FOUR HELICAL-BUNDLE STRUCTURE OF THE CYTOPLASMIC DOMAIN OF A SERINE CHEMOTAXIS RECEPTOR
Keywords keywords	SERINE, CHEMOTAXIS, FOUR HELICAL-BUNDLE, SIGNALING PROTEIN; SIGNALING PROTEIN
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.

1qu7__assembly_1__model_1

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

Download this curve (.dat)

1qu7__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1qu7__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	48.30 Å
Rg (electron density)	51.65 Å
Total Rg	50.30 Å
Atom count	3243
Residues	448
Excluded volume	56850 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1qu7__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 (2)

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6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

Domain ID domain_id	d1qu7a_
Class class	h — Coiled coil proteins
Fold Fold fold	h.4 — Antiparallel coiled-coil
Superfamily Superfamily superfamily	h.4.5 — Methyl-accepting chemotaxis protein (MCP) signaling domain
Family Family family	h.4.5.1 — Methyl-accepting chemotaxis protein (MCP) signaling domain

Domain ID domain_id	d1qu7b_
Class class	h — Coiled coil proteins
Fold Fold fold	h.4 — Antiparallel coiled-coil
Superfamily Superfamily superfamily	h.4.5 — Methyl-accepting chemotaxis protein (MCP) signaling domain
Family Family family	h.4.5.1 — Methyl-accepting chemotaxis protein (MCP) signaling domain

CATH v4.4 (2 domains)

Domain ID domain_id	1qu7A00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	287 — Helix Hairpins
Homologous superfamily homologous superfamily	950 — Methyl-accepting chemotaxis protein

Domain ID domain_id	1qu7B00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	287 — Helix Hairpins
Homologous superfamily homologous superfamily	950 — Methyl-accepting chemotaxis protein

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Unit-cell length a length_a	132.440 Å
Unit-cell length b length_b	132.440 Å
Unit-cell length c length_c	134.590 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.00 °
Unit-cell angle γ angle_gamma	120.00 °
Molecules per unit cell Z z_pdb	12

Space group space_group	P 3 2 1
Space-group number int_tables_number	150
Crystal system crystal_system	—

Resolution resolution	2.600 Å
Low-resolution limit resolution_low	100.000 Å
R factor r_factor	0.2430
R_work r_work	0.2430
R_free r_free	0.2760

Description description	METHYL-ACCEPTING CHEMOTAXIS PROTEIN I
Molecular weight formula_weight	23741.3 kDa
Source method src_method	man
Copy count entity_count	2

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B
Atom count atom_count	3430

FOUR HELICAL-BUNDLE STRUCTURE OF THE CYTOPLASMIC DOMAIN OF A SERINE CHEMOTAXIS RECEPTOR

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

METHYL-ACCEPTING CHEMOTAXIS PROTEIN I

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

1qu7__assembly_1__model_1

1qu7__assembly_1__model_1 | I(q)

1qu7__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 (2)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 water

6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)

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

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	187

FOUR HELICAL-BUNDLE STRUCTURE OF THE CYTOPLASMIC DOMAIN OF A SERINE CHEMOTAXIS RECEPTOR

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

METHYL-ACCEPTING CHEMOTAXIS PROTEIN I

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

1qu7__assembly_1__model_1

1qu7__assembly_1__model_1 | I(q)

1qu7__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 (2)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 water

6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)