SAXSdb — 3c1d

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

Regulatory protein recX

Escherichia coli

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein monomer	Monomer	Protein 1	water × 1	Consistent with protein count
2	Protein monomer	Monomer	Protein 1	water × 1	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	RECX_ECO57
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 2–159； UniProt 9–166 Author chain B； PDBConstruct 2–159； UniProt 9–166

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	3c1d
Deposition date deposition_date	2008-01-23
Structure title title	X-ray crystal structure of RecX
Keywords keywords	tandem repeats, helix-turn-helix, Cytoplasm, DNA damage, DNA repair, SOS response, DNA BINDING PROTEIN, RECOMBINATION; RECOMBINATION, DNA BINDING 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.

3c1d__assembly_2__model_1

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

Download this curve (.dat)

3c1d__assembly_2__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

3c1d__assembly_2__model_1 | P(r) · Pending

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

Rg（Guinier）	21.22 Å
Rg (electron density)	21.10 Å
Total Rg	21.78 Å
Atom count	1258
Residues	154
Excluded volume	22183 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`3c1d__assembly_1__model_1`	monomeric （1）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`3c1d__assembly_2__model_1`	monomeric （1）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`3c1d__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 (2)

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6. Fold Classification (SCOP + CATH) 6 domains

CATH v4.4 (6 domains)

Domain ID domain_id	3c1dA01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	10 — Arc Repressor Mutant, subunit A
Homologous superfamily homologous superfamily	10 — Winged helix-like DNA-binding domain superfamily/Winged helix DNA-binding domain

Domain ID domain_id	3c1dA02
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	10 — Arc Repressor Mutant, subunit A
Homologous superfamily homologous superfamily	10 — Winged helix-like DNA-binding domain superfamily/Winged helix DNA-binding domain

Domain ID domain_id	3c1dA03
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	10 — Arc Repressor Mutant, subunit A
Homologous superfamily homologous superfamily	10 — Winged helix-like DNA-binding domain superfamily/Winged helix DNA-binding domain

Domain ID domain_id	3c1dB01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	10 — Arc Repressor Mutant, subunit A
Homologous superfamily homologous superfamily	10 — Winged helix-like DNA-binding domain superfamily/Winged helix DNA-binding domain

Domain ID domain_id	3c1dB02
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	10 — Arc Repressor Mutant, subunit A
Homologous superfamily homologous superfamily	10 — Winged helix-like DNA-binding domain superfamily/Winged helix DNA-binding domain

Domain ID domain_id	3c1dB03
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	10 — Arc Repressor Mutant, subunit A
Homologous superfamily homologous superfamily	10 — Winged helix-like DNA-binding domain superfamily/Winged helix DNA-binding domain

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Unit-cell length a length_a	55.549 Å
Unit-cell length b length_b	71.757 Å
Unit-cell length c length_c	74.657 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	8

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

Resolution resolution	1.800 Å
Low-resolution limit resolution_low	16.500 Å
R factor r_factor	0.1820
R_work r_work	0.1800
R_free r_free	0.2230

Description description	Regulatory protein recX
Molecular weight formula_weight	18485.0 kDa
Mutation mutation	C113A, C118A
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	2870

X-ray crystal structure of RecX

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

Regulatory protein recX

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

3c1d__assembly_2__model_1

3c1d__assembly_2__model_1 | I(q)

3c1d__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 (2)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 water

6. Fold Classification (SCOP + CATH) 6 domains

CATH v4.4 (6 domains)

7. Citations (1)

Source organism organism	Escherichia coli
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	311

X-ray crystal structure of RecX

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

Regulatory protein recX

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

3c1d__assembly_2__model_1

3c1d__assembly_2__model_1 | I(q)

3c1d__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 (2)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 water

6. Fold Classification (SCOP + CATH) 6 domains

CATH v4.4 (6 domains)

7. Citations (1)