SAXSdb — 1i5n

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

CHEMOTAXIS PROTEIN CHEA

Salmonella typhimurium

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein monomer	Monomer	Protein 1	SULFATE ION × 1 water × 1	Consistent with protein count
2	Protein monomer	Monomer	Protein 1	water × 1	Consistent with protein count
3	Protein monomer	Monomer	Protein 1	water × 1	Consistent with protein count
4	Protein monomer	Monomer	Protein 1	water × 1	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	CHEA_SALTY
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–138； UniProt 1–138 Author chain B； PDBConstruct 1–138； UniProt 1–138 Author chain C； PDBConstruct 1–138； UniProt 1–138 Author chain D； PDBConstruct 1–138； UniProt 1–138

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	1i5n
Deposition date deposition_date	2001-02-28
Structure title title	Crystal structure of the P1 domain of CheA from Salmonella typhimurium
Keywords keywords	Four-helix bundle, TRANSFERASE; TRANSFERASE
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.

1i5n__assembly_3__model_1

Assembly 3 · Model 1 · CRYSOL 4.1.3-1-20251215 (887e7ef)

Download this curve (.dat)

1i5n__assembly_3__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1i5n__assembly_3__model_1 | P(r) · Pending

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

Rg（Guinier）	15.36 Å
Rg (electron density)	14.18 Å
Total Rg	15.07 Å
Atom count	997
Residues	121
Excluded volume	17612 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1i5n__assembly_1__model_1`	monomeric （1）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`1i5n__assembly_2__model_1`	monomeric （1）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`1i5n__assembly_3__model_1`	monomeric （1）	Success	4.1.3-1-20251215 (887e7ef)	View Download
4	1	`1i5n__assembly_4__model_1`	monomeric （1）	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 (3)

Entity 1 Entity 1 polymer

Description description	CHEMOTAXIS PROTEIN CHEA
Molecular weight formula_weight	16902.8 kDa
EC 编号 ec_number	2.7.3.-
Source method src_method	man
Copy count entity_count	4

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,C,D
Atom count atom_count	4244

MSMDISDFYQTFFDEADELLADMEQHLLDLVPESPDAEQLNAIFRAAHSIKGGAGTFGFTILQETTHLMENLLDEARRGEMQLNTDIINLFLETKDIMQEQLDAYKNSEEPDAASFEYICNALRQLALEAKGETTPAVRSHHHHHH

Source Source

Source organism organism	Salmonella typhimurium
NCBI taxonomy ID ncbi_taxonomy_id	602
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 non-polymer

Description description	SULFATE ION
Molecular weight formula_weight	96.1 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 3 Entity 3 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	215

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6. Fold Classification (SCOP + CATH) 8 domains

SCOP 2.08 (4 domains)

Domain ID domain_id	d1i5na_
Class class	a — All alpha proteins
Fold Fold fold	a.24 — Four-helical up-and-down bundle
Superfamily Superfamily superfamily	a.24.10 — Histidine-containing phosphotransfer domain, HPT domain
Family Family family	a.24.10.3 — Chemotaxis protein CheA P1 domain

Domain ID domain_id	d1i5nb_
Class class	a — All alpha proteins
Fold Fold fold	a.24 — Four-helical up-and-down bundle
Superfamily Superfamily superfamily	a.24.10 — Histidine-containing phosphotransfer domain, HPT domain
Family Family family	a.24.10.3 — Chemotaxis protein CheA P1 domain

Domain ID domain_id	d1i5nc_
Class class	a — All alpha proteins
Fold Fold fold	a.24 — Four-helical up-and-down bundle
Superfamily Superfamily superfamily	a.24.10 — Histidine-containing phosphotransfer domain, HPT domain
Family Family family	a.24.10.3 — Chemotaxis protein CheA P1 domain

Domain ID domain_id	d1i5nd_
Class class	a — All alpha proteins
Fold Fold fold	a.24 — Four-helical up-and-down bundle
Superfamily Superfamily superfamily	a.24.10 — Histidine-containing phosphotransfer domain, HPT domain
Family Family family	a.24.10.3 — Chemotaxis protein CheA P1 domain

CATH v4.4 (4 domains)

Domain ID domain_id	1i5nA00
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	120 — Four Helix Bundle (Hemerythrin (Met), subunit A)
Homologous superfamily homologous superfamily	160 — HPT domain

Domain ID domain_id	1i5nB00
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	120 — Four Helix Bundle (Hemerythrin (Met), subunit A)
Homologous superfamily homologous superfamily	160 — HPT domain

Domain ID domain_id	1i5nC00
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	120 — Four Helix Bundle (Hemerythrin (Met), subunit A)
Homologous superfamily homologous superfamily	160 — HPT domain

Domain ID domain_id	1i5nD00
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	120 — Four Helix Bundle (Hemerythrin (Met), subunit A)
Homologous superfamily homologous superfamily	160 — HPT domain

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Unit-cell length a length_a	54.950 Å
Unit-cell length b length_b	88.720 Å
Unit-cell length c length_c	115.820 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	16

Space group space_group	P 21 21 21
Space-group number int_tables_number	19
Crystal system crystal_system	—

Resolution resolution	2.140 Å
Low-resolution limit resolution_low	35.300 Å
R factor r_factor	0.2120
R_work r_work	0.2100
R_free r_free	0.2480

Crystal structure of the P1 domain of CheA from Salmonella typhimurium

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

CHEMOTAXIS PROTEIN CHEA

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

1i5n__assembly_3__model_1

1i5n__assembly_3__model_1 | I(q)

1i5n__assembly_3__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 (3)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 water

6. Fold Classification (SCOP + CATH) 8 domains

SCOP 2.08 (4 domains)

CATH v4.4 (4 domains)

7. Citations (2)

Crystal structure of the P1 domain of CheA from Salmonella typhimurium

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

CHEMOTAXIS PROTEIN CHEA

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

1i5n__assembly_3__model_1

1i5n__assembly_3__model_1 | I(q)

1i5n__assembly_3__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 (3)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 water

6. Fold Classification (SCOP + CATH) 8 domains

SCOP 2.08 (4 domains)

CATH v4.4 (4 domains)

7. Citations (2)