1b9n

REGULATOR FROM ESCHERICHIA COLI

Method: X-RAY DIFFRACTION

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

PROTEIN (MODE)

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	NICKEL (II) ION × 1 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	MODE_ECOLI
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 4–265； UniProt 1–262 Author chain B； PDBConstruct 4–265； UniProt 1–262

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	1b9n
Deposition date deposition_date	1999-02-12
Structure title title	REGULATOR FROM ESCHERICHIA COLI
Keywords keywords	DNA-BINDING, GENE REGULATION, WINGED HELIX TURN HELIX, MOLYBDATE, OB FOLD, TRANSCRIPTION; TRANSCRIPTION
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.

1b9n__assembly_1__model_1

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

Download this curve (.dat)

1b9n__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1b9n__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	27.86 Å
Rg (electron density)	26.73 Å
Total Rg	27.40 Å
Atom count	3795
Residues	503
Excluded volume	67780 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1b9n__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 (3)

Entity 1 Entity 1 polymer

Description description	PROTEIN (MODE)
Molecular weight formula_weight	28590.4 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B
Atom count atom_count	4132

GSHMQAEILLTLKLQQKLFADPRRISLLKHIALSGSISQGAKDAGISYKSAWDAINEMNQLSEHILVERATGGKGGGGAVLTRYGQRLIQLYDLLAQIQQKAFDVLSDDDALPLNSLLAAISRFSLQTSARNQWFGTITARDHDDVQQHVDVLLADGKTRLKVAITAQSGARLGLDEGKEVLILLKAPWVGITQDEAVAQNADNQLPGIISHIERGAEQCEVLMALPDGQTLCATVPVNEATSLQQGQNVTAYFNADSVIIATLC

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	NICKEL (II) ION
Molecular weight formula_weight	58.7 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	309

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6. Fold Classification (SCOP + CATH) 12 domains

SCOP 2.08 (6 domains)

Domain ID domain_id	d1b9na1
Class class	a — All alpha proteins
Fold Fold fold	a.4 — DNA/RNA-binding 3-helical bundle
Superfamily Superfamily superfamily	a.4.5 — 'Winged helix' DNA-binding domain
Family Family family	a.4.5.8 — N-terminal domain of molybdate-dependent transcriptional regulator ModE

Domain ID domain_id	d1b9na3
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.6 — MOP-like
Family Family family	b.40.6.2 — BiMOP, duplicated molybdate-binding domain

Domain ID domain_id	d1b9na4
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.6 — MOP-like
Family Family family	b.40.6.2 — BiMOP, duplicated molybdate-binding domain

Domain ID domain_id	d1b9nb1
Class class	a — All alpha proteins
Fold Fold fold	a.4 — DNA/RNA-binding 3-helical bundle
Superfamily Superfamily superfamily	a.4.5 — 'Winged helix' DNA-binding domain
Family Family family	a.4.5.8 — N-terminal domain of molybdate-dependent transcriptional regulator ModE

Domain ID domain_id	d1b9nb3
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.6 — MOP-like
Family Family family	b.40.6.2 — BiMOP, duplicated molybdate-binding domain

Domain ID domain_id	d1b9nb4
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.6 — MOP-like
Family Family family	b.40.6.2 — BiMOP, duplicated molybdate-binding domain

CATH v4.4 (6 domains)

Domain ID domain_id	1b9nA01
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	1b9nA02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	100 — RNA polymerase II/Efflux pump adaptor protein, barrel-sandwich hybrid domain

Domain ID domain_id	1b9nA03
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	100 — RNA polymerase II/Efflux pump adaptor protein, barrel-sandwich hybrid domain

Domain ID domain_id	1b9nB01
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	1b9nB02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	100 — RNA polymerase II/Efflux pump adaptor protein, barrel-sandwich hybrid domain

Domain ID domain_id	1b9nB03
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	100 — RNA polymerase II/Efflux pump adaptor protein, barrel-sandwich hybrid domain

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Unit-cell length a length_a	81.110 Å
Unit-cell length b length_b	127.360 Å
Unit-cell length c length_c	62.950 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 2
Space-group number int_tables_number	18
Crystal system crystal_system	—

Resolution resolution	2.090 Å
Low-resolution limit resolution_low	28.630 Å
R factor r_factor	—
R_work r_work	0.2140
R_free r_free	0.2860

REGULATOR FROM ESCHERICHIA COLI

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

PROTEIN (MODE)

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

1b9n__assembly_1__model_1

1b9n__assembly_1__model_1 | I(q)

1b9n__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 (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) 12 domains

SCOP 2.08 (6 domains)

CATH v4.4 (6 domains)

7. Citations (3)

REGULATOR FROM ESCHERICHIA COLI

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

PROTEIN (MODE)

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

1b9n__assembly_1__model_1

1b9n__assembly_1__model_1 | I(q)

1b9n__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 (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) 12 domains

SCOP 2.08 (6 domains)

CATH v4.4 (6 domains)

7. Citations (3)