SAXSdb — 1qjg

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

KETOSTEROID ISOMERASE

PSEUDOMONAS TESTOSTERONI

State in the Current Structure

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

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	SDIS_COMTE
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–125； UniProt 1–125 Author chain B； PDBConstruct 1–125； UniProt 1–125 Author chain C； PDBConstruct 1–125； UniProt 1–125 Author chain D； PDBConstruct 1–125； UniProt 1–125 Author chain E； PDBConstruct 1–125； UniProt 1–125 Author chain F； PDBConstruct 1–125； UniProt 1–125

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	1qjg
Deposition date deposition_date	1999-06-24
Structure title title	Crystal structure of delta5-3-ketosteroid isomerase from Pseudomonas testosteroni in complex with equilenin
Keywords keywords	KETOSTEROID ISOMERASE, KSI, ISOMERASE, STEROID ISOMERATION; ISOMERASE
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.

1qjg__assembly_1__model_1

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

Download this curve (.dat)

1qjg__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1qjg__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	19.63 Å
Rg (electron density)	18.48 Å
Total Rg	19.46 Å
Atom count	2352
Residues	250
Excluded volume	34378 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1qjg__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`1qjg__assembly_2__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`1qjg__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 (4)

Entity 1 Entity 1 polymer

Description description	KETOSTEROID ISOMERASE
Molecular weight formula_weight	13423.2 kDa
Mutation mutation	YES
Source method src_method	man
Copy count entity_count	6

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,C,D,E,F
Atom count atom_count	7509

MNTPEHMTAVVQRYVAALNAGDLDGIVALFADDATVENPVGSEPRSGTAAIREFYANSLKLPLAVELTQEVRAVANEAAFAFIVSFEYQGRKTVVAPIDHFRFNGAGKVVSMRALFGEKNIHAGA

Source Source

Source organism organism	PSEUDOMONAS TESTOSTERONI
NCBI taxonomy ID ncbi_taxonomy_id	285
Host organism host_organism	ESCHERICHIA COLI

Entity 2 Entity 2 non-polymer

Description description	EQUILENIN
Molecular weight formula_weight	266.3 kDa
Source method src_method	syn
Copy count entity_count	6

Entity 3 Entity 3 non-polymer

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

Entity 4 Entity 4 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	155

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6. Fold Classification (SCOP + CATH) 12 domains

SCOP 2.08 (6 domains)

Domain ID domain_id	d1qjga_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.17 — Cystatin-like
Superfamily Superfamily superfamily	d.17.4 — NTF2-like
Family Family family	d.17.4.3 — Ketosteroid isomerase-like

Domain ID domain_id	d1qjgb_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.17 — Cystatin-like
Superfamily Superfamily superfamily	d.17.4 — NTF2-like
Family Family family	d.17.4.3 — Ketosteroid isomerase-like

Domain ID domain_id	d1qjgc_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.17 — Cystatin-like
Superfamily Superfamily superfamily	d.17.4 — NTF2-like
Family Family family	d.17.4.3 — Ketosteroid isomerase-like

Domain ID domain_id	d1qjgd_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.17 — Cystatin-like
Superfamily Superfamily superfamily	d.17.4 — NTF2-like
Family Family family	d.17.4.3 — Ketosteroid isomerase-like

Domain ID domain_id	d1qjge_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.17 — Cystatin-like
Superfamily Superfamily superfamily	d.17.4 — NTF2-like
Family Family family	d.17.4.3 — Ketosteroid isomerase-like

Domain ID domain_id	d1qjgf_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.17 — Cystatin-like
Superfamily Superfamily superfamily	d.17.4 — NTF2-like
Family Family family	d.17.4.3 — Ketosteroid isomerase-like

CATH v4.4 (6 domains)

Domain ID domain_id	1qjgA00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	450 — Nuclear Transport Factor 2; Chain: A,
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	1qjgB00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	450 — Nuclear Transport Factor 2; Chain: A,
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	1qjgC00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	450 — Nuclear Transport Factor 2; Chain: A,
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	1qjgD00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	450 — Nuclear Transport Factor 2; Chain: A,
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	1qjgE00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	450 — Nuclear Transport Factor 2; Chain: A,
Homologous superfamily homologous superfamily	50 —

Domain ID domain_id	1qjgF00
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	450 — Nuclear Transport Factor 2; Chain: A,
Homologous superfamily homologous superfamily	50 —

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Unit-cell length a length_a	73.900 Å
Unit-cell length b length_b	72.500 Å
Unit-cell length c length_c	80.800 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	104.30 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	12

Space group space_group	P 1 21 1
Space-group number int_tables_number	4
Crystal system crystal_system	—

Resolution resolution	2.300 Å
Low-resolution limit resolution_low	10.000 Å
R factor r_factor	0.2050
R_work r_work	0.2050
R_free r_free	0.2710

Crystal structure of delta5-3-ketosteroid isomerase from Pseudomonas testosteroni in complex with equilenin

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

KETOSTEROID ISOMERASE

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

1qjg__assembly_1__model_1

1qjg__assembly_1__model_1 | I(q)

1qjg__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 (4)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

6. Fold Classification (SCOP + CATH) 12 domains

SCOP 2.08 (6 domains)

CATH v4.4 (6 domains)

7. Citations (2)

Crystal structure of delta5-3-ketosteroid isomerase from Pseudomonas testosteroni in complex with equilenin

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

KETOSTEROID ISOMERASE

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

1qjg__assembly_1__model_1

1qjg__assembly_1__model_1 | I(q)

1qjg__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 (4)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

6. Fold Classification (SCOP + CATH) 12 domains

SCOP 2.08 (6 domains)

CATH v4.4 (6 domains)

7. Citations (2)