SAXSdb — 3epu

▼

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

STM2138 Virulence Chaperone

Salmonella typhimurium

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 4	water × 2	Consistent with protein count
2	Protein homooligomer	Homooligomer	Protein 2	water × 1	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	Q8ZNP3_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

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.

▼

2. Structure Basics 2. Structure Basics

Entry ID entry_id	3epu
Deposition date deposition_date	2008-09-30
Structure title title	Crystal Structure of STM2138, a novel virulence chaperone in Salmonella
Keywords keywords	Virulence Chaperone, Salmonella, TypeIII Secretion System, STM2138, SrcA (SsrB-regulated chaperone A), CHAPERONE; CHAPERONE
Experimental Method method	X-RAY DIFFRACTION

▼

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.

3epu__assembly_2__model_1

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

Download this curve (.dat)

3epu__assembly_2__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

3epu__assembly_2__model_1 | P(r) · Pending

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

Rg（Guinier）	21.89 Å
Rg (electron density)	20.83 Å
Total Rg	21.79 Å
Atom count	2174
Residues	267
Excluded volume	38581 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`3epu__assembly_1__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`3epu__assembly_2__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download

▶

4. Crystallography and Experiment 4. Crystallography & Experiment

▶

5. Entities and Polymers Entities & Polymers (2)

▼

6. Fold Classification (SCOP + CATH) 5 domains

SCOP 2.08 (2 domains)

Domain ID domain_id	d3epua_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.198 — Secretion chaperone-like
Superfamily Superfamily superfamily	d.198.1 — Type III secretory system chaperone-like
Family Family family	d.198.1.0 — automated matches

Domain ID domain_id	d3epub_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.198 — Secretion chaperone-like
Superfamily Superfamily superfamily	d.198.1 — Type III secretory system chaperone-like
Family Family family	d.198.1.0 — automated matches

CATH v4.4 (3 domains)

Domain ID domain_id	3epuA00
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	1460 — Yope Regulator; Chain: A,
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	3epuB01
Class class	6 — Special
Architecture architecture	10 — Helix non-globular
Topology topology	250 — Single alpha-helices involved in coiled-coils or other helix-helix interfaces
Homologous superfamily homologous superfamily	740 —

Domain ID domain_id	3epuB02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	1460 — Yope Regulator; Chain: A,
Homologous superfamily homologous superfamily	10 —

▶

Unit-cell length a length_a	103.838 Å
Unit-cell length b length_b	46.832 Å
Unit-cell length c length_c	65.936 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	106.39 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	8

Space group space_group	C 1 2 1
Space-group number int_tables_number	5
Crystal system crystal_system	—

Resolution resolution	2.500 Å
Low-resolution limit resolution_low	33.400 Å
R factor r_factor	0.2163
R_work r_work	0.2145
R_free r_free	0.2526

Description description	STM2138 Virulence Chaperone
Molecular weight formula_weight	16907.0 kDa
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	2260

Crystal Structure of STM2138, a novel virulence chaperone in Salmonella

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

STM2138 Virulence Chaperone

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

3epu__assembly_2__model_1

3epu__assembly_2__model_1 | I(q)

3epu__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) 5 domains

SCOP 2.08 (2 domains)

CATH v4.4 (3 domains)

7. Citations (1)

Source organism organism	Salmonella typhimurium
NCBI taxonomy ID ncbi_taxonomy_id	602
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	86

Crystal Structure of STM2138, a novel virulence chaperone in Salmonella

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

STM2138 Virulence Chaperone

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

3epu__assembly_2__model_1

3epu__assembly_2__model_1 | I(q)

3epu__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) 5 domains

SCOP 2.08 (2 domains)

CATH v4.4 (3 domains)

7. Citations (1)