SAXSdb — 2v9a

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

SENSOR KINASE CITA

KLEBSIELLA PNEUMONIAE

State in the Current Structure

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

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	CITA_KLEPN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 2–133； UniProt 45–176 Author chain B； PDBConstruct 2–133； UniProt 45–176

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	2v9a
Deposition date deposition_date	2007-08-23
Structure title title	Structure of Citrate-free Periplasmic Domain of Sensor Histidine Kinase CitA
Keywords keywords	;SIGNAL TRANSDUCTION, SENSOR HISTIDINE KINASE, CITA, KINASE, MEMBRANE, TRANSFERASE, SENSOR DOMAIN, TRANSMEMBRANE, INNER MEMBRANE, PHOSPHORYLATION, TWO-COMPONENT REGULATORY SYSTEM ;; TRANSFERASE
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.

2v9a__assembly_2__model_1

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

Download this curve (.dat)

2v9a__assembly_2__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

2v9a__assembly_2__model_1 | P(r) · Pending

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

Rg（Guinier）	22.54 Å
Rg (electron density)	21.57 Å
Total Rg	22.54 Å
Atom count	2992
Residues	424
Excluded volume	53350 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`2v9a__assembly_1__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`2v9a__assembly_2__model_1`	tetrameric （4）	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) 4 domains

SCOP 2.08 (2 domains)

Domain ID domain_id	d2v9aa_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.110 — Profilin-like
Superfamily Superfamily superfamily	d.110.6 — Sensory domain-like
Family Family family	d.110.6.1 — Sensory domain of two-component sensor kinase

Domain ID domain_id	d2v9ab_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.110 — Profilin-like
Superfamily Superfamily superfamily	d.110.6 — Sensory domain-like
Family Family family	d.110.6.1 — Sensory domain of two-component sensor kinase

CATH v4.4 (2 domains)

Domain ID domain_id	2v9aA00
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	450 — Beta-Lactamase
Homologous superfamily homologous superfamily	20 — PAS domain

Domain ID domain_id	2v9aB00
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	450 — Beta-Lactamase
Homologous superfamily homologous superfamily	20 — PAS domain

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Unit-cell length a length_a	64.163 Å
Unit-cell length b length_b	64.163 Å
Unit-cell length c length_c	144.746 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	16

Space group space_group	I 4
Space-group number int_tables_number	79
Crystal system crystal_system	—

Resolution resolution	2.000 Å
Low-resolution limit resolution_low	24.663 Å
R factor r_factor	—
R_work r_work	0.2124
R_free r_free	0.2783

Description description	SENSOR KINASE CITA
Molecular weight formula_weight	14499.4 kDa
EC 编号 ec_number	2.7.13.3
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	1725

Structure of Citrate-free Periplasmic Domain of Sensor Histidine Kinase CitA

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

SENSOR KINASE CITA

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

2v9a__assembly_2__model_1

2v9a__assembly_2__model_1 | I(q)

2v9a__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) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)

Source organism organism	KLEBSIELLA PNEUMONIAE
NCBI taxonomy ID ncbi_taxonomy_id	573
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	229

Structure of Citrate-free Periplasmic Domain of Sensor Histidine Kinase CitA

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

SENSOR KINASE CITA

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

2v9a__assembly_2__model_1

2v9a__assembly_2__model_1 | I(q)

2v9a__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) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)