SAXSdb — 1xrx

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

SeqA protein

Escherichia coli

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 8	CALCIUM ION × 2 water × 8	Consistent with protein count
2	Protein homooligomer	Homooligomer	Protein 2	CALCIUM ION × 1 water × 2	Consistent with protein count
3	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	SEQA_ECOLI
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–50； UniProt 1–50 Author chain B； PDBConstruct 1–50； UniProt 1–50 Author chain C； PDBConstruct 1–50； UniProt 1–50 Author chain D； PDBConstruct 1–50； UniProt 1–50

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	1xrx
Deposition date deposition_date	2004-10-16
Structure title title	Crystal structure of a DNA-binding protein
Keywords keywords	Protein filament, Left-handed helix, DNA replication inhibitor, REPLICATION INHIBITOR; REPLICATION INHIBITOR
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.

1xrx__assembly_1__model_1

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

Download this curve (.dat)

1xrx__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1xrx__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	32.24 Å
Rg (electron density)	33.40 Å
Total Rg	33.21 Å
Atom count	2290
Residues	264
Excluded volume	41273 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1xrx__assembly_1__model_1`	octameric （8）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`1xrx__assembly_2__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`1xrx__assembly_3__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 (3)

Entity 1 Entity 1 polymer

Description description	SeqA protein
Molecular weight formula_weight	5695.2 kDa
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	1328

MKTIEVDDELYSYIASHTKHIGESASDILRRMLKFSAASQPAAPVTKEVR

Source Source

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

Entity 2 Entity 2 non-polymer

Description description	CALCIUM ION
Molecular weight formula_weight	40.1 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	175

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6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (4 domains)

Domain ID domain_id	d1xrxa1
Class class	a — All alpha proteins
Fold Fold fold	a.43 — Ribbon-helix-helix
Superfamily Superfamily superfamily	a.43.1 — Ribbon-helix-helix
Family Family family	a.43.1.7 — SeqA N-terminal domain-like

Domain ID domain_id	d1xrxb_
Class class	a — All alpha proteins
Fold Fold fold	a.43 — Ribbon-helix-helix
Superfamily Superfamily superfamily	a.43.1 — Ribbon-helix-helix
Family Family family	a.43.1.7 — SeqA N-terminal domain-like

Domain ID domain_id	d1xrxc_
Class class	a — All alpha proteins
Fold Fold fold	a.43 — Ribbon-helix-helix
Superfamily Superfamily superfamily	a.43.1 — Ribbon-helix-helix
Family Family family	a.43.1.7 — SeqA N-terminal domain-like

Domain ID domain_id	d1xrxd_
Class class	a — All alpha proteins
Fold Fold fold	a.43 — Ribbon-helix-helix
Superfamily Superfamily superfamily	a.43.1 — Ribbon-helix-helix
Family Family family	a.43.1.7 — SeqA N-terminal domain-like

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Unit-cell length a length_a	112.179 Å
Unit-cell length b length_b	112.179 Å
Unit-cell length c length_c	62.021 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	24

Space group space_group	P 31 2 1
Space-group number int_tables_number	152
Crystal system crystal_system	—

Resolution resolution	2.150 Å
Low-resolution limit resolution_low	24.710 Å
R factor r_factor	—
R_work r_work	0.2220
R_free r_free	0.2370

Crystal structure of a DNA-binding protein

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

SeqA protein

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

1xrx__assembly_1__model_1

1xrx__assembly_1__model_1 | I(q)

1xrx__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

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) 4 domains

SCOP 2.08 (4 domains)

7. Citations (1)

Crystal structure of a DNA-binding protein

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

SeqA protein

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

1xrx__assembly_1__model_1

1xrx__assembly_1__model_1 | I(q)

1xrx__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

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) 4 domains

SCOP 2.08 (4 domains)

7. Citations (1)