SAXSdb — 3a0r

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

Sensor protein

Thermotoga maritima

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 4	Response regulator × 2 （Q9X181） MERCURY (II) ION × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	Q9X180_THEMA
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 2–349； UniProt 408–755

Response regulator

Thermotoga maritima

UniProt Q9X181

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 4	Sensor protein × 2 （Q9X180） MERCURY (II) ION × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	Q9X181_THEMA
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 1–116； UniProt 1–116

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	3a0r
Deposition date deposition_date	2009-03-24
Structure title title	Crystal structure of histidine kinase ThkA (TM1359) in complex with response regulator protein TrrA (TM1360)
Keywords keywords	four helix bundle, PAS fold, Kinase, Phosphoprotein, Transferase, 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.

3a0r__assembly_1__model_1

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

Download this curve (.dat)

3a0r__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

3a0r__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	33.94 Å
Rg (electron density)	33.33 Å
Total Rg	33.82 Å
Atom count	7418
Residues	894
Excluded volume	133440 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`3a0r__assembly_1__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 (3)

Entity 1 Entity 1 polymer

Description description	Sensor protein
Molecular weight formula_weight	40999.0 kDa
EC 编号 ec_number	2.7.13.3
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A
Atom count atom_count	3709

MLVEHLRNFSESILESLETAIITLSKDGRITEWNKKAEQLFGLKKENVLGRRLKDLPDFEEIGSVAESVFENKEPVFLNFYKFGERYFNIRFSPFRNAKTQLLEGVIITIDDVTELYKYEEERKRRERLSILGEMTARVAHEIRNPITIIGGFIMRMKKHLDDPETLKKYINIITNELSRLETIVKEILEYSKERQVLEFTEFNLNELIREVYVLFEEKIRKMNIDFCFETDNEDLRVEADRTRIKQVLINLVQNAIEATGENGKIKITSEDMYTKVRVSVWNSGPPIPEELKEKIFSPFFTTKTQGTGLGLSICRKIIEDEHGGKIWTENRENGVVFIFEIPKTPEKR

Source Source

Source organism organism	Thermotoga maritima
NCBI taxonomy ID ncbi_taxonomy_id	2336
Host organism host_organism	Escherichia coli BL21(DE3)

Entity 2 Entity 2 polymer

Description description	Response regulator
Molecular weight formula_weight	13521.0 kDa
Mutation mutation	L89M
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B

MKRILVVDDEPNIRELLKEELQEEGYEIDTAENGEEALKKFFSGNYDLVILDIEMPGISGLEVAGEIRKKKKDAKIILLTAYSHYRSDMSSWAADEYVVKSFNFDELKEKVKKLLS

Source Source

Source organism organism	Thermotoga maritima
NCBI taxonomy ID ncbi_taxonomy_id	2336
Host organism host_organism	Escherichia coli BL21(DE3)

Entity 3 Entity 3 non-polymer

Description description	MERCURY (II) ION
Molecular weight formula_weight	200.6 kDa
Source method src_method	syn
Copy count entity_count	1

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6. Fold Classification (SCOP + CATH) 4 domains

CATH v4.4 (4 domains)

Domain ID domain_id	3a0rA01
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	3a0rA02
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	287 — Helix Hairpins
Homologous superfamily homologous superfamily	130 — Signal transduction histidine kinase, dimerisation/phosphotransfer (DHp) domain

Domain ID domain_id	3a0rA03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	565 — Heat Shock Protein 90
Homologous superfamily homologous superfamily	10 — Histidine kinase-like ATPase, C-terminal domain

Domain ID domain_id	3a0rB00
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	2300 — Response regulator

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Unit-cell length a length_a	110.594 Å
Unit-cell length b length_b	110.594 Å
Unit-cell length c length_c	352.508 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 41 2 2
Space-group number int_tables_number	98
Crystal system crystal_system	—

Resolution resolution	3.800 Å
Low-resolution limit resolution_low	20.000 Å
R factor r_factor	0.3509
R_work r_work	0.3500
R_free r_free	0.3710

Crystal structure of histidine kinase ThkA (TM1359) in complex with response regulator protein TrrA (TM1360)

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

Sensor protein

State in the Current Structure

Other States of the Same Protein in the Database

Response regulator

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

3a0r__assembly_1__model_1

3a0r__assembly_1__model_1 | I(q)

3a0r__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 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

6. Fold Classification (SCOP + CATH) 4 domains

CATH v4.4 (4 domains)

7. Citations (2)

Crystal structure of histidine kinase ThkA (TM1359) in complex with response regulator protein TrrA (TM1360)

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

Sensor protein

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Response regulator

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

3a0r__assembly_1__model_1

3a0r__assembly_1__model_1 | I(q)

3a0r__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 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

6. Fold Classification (SCOP + CATH) 4 domains

CATH v4.4 (4 domains)

7. Citations (2)