2grx

Crystal structure of TonB in complex with FhuA, E. coli outer membrane receptor for ferrichrome

Method: X-RAY DIFFRACTION

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

Ferrichrome-iron receptor

Escherichia coli

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Other combination	Heteromer	Protein 2 其他Polymer 1	Protein tonB × 1 （P94739） ;3-deoxy-alpha-D-manno-oct-2-ulopyranosonic acid-(2-4)-[L-glycero-alpha-D-manno-heptopyranose-(1-5)]3-deoxy-alpha-D-manno-oct-2-ulopyranosonic acid-(2-6)-2-amino-2,3-dideoxy-alpha-D-glucoyranose-(1-6)-2-amino-2,3-dideoxy-alpha-D-glucoyranose ; × 1 PHOSPHATE ION × 1 3-HYDROXY-TETRADECANOIC ACID × 4 DIPHOSPHATE × 1 LAURIC ACID × 1 2-AMINO-VINYL-PHOSPHATE × 1 FERRICROCIN-IRON × 1	Consistent with protein count
2	Other combination	Heteromer	Protein 2 其他Polymer 1	Protein tonB × 1 （P94739） ;3-deoxy-alpha-D-manno-oct-2-ulopyranosonic acid-(2-4)-[L-glycero-alpha-D-manno-heptopyranose-(1-5)]3-deoxy-alpha-D-manno-oct-2-ulopyranosonic acid-(2-6)-2-amino-2,3-dideoxy-alpha-D-glucoyranose-(1-6)-2-amino-2,3-dideoxy-alpha-D-glucoyranose ; × 1 PHOSPHATE ION × 1 3-HYDROXY-TETRADECANOIC ACID × 4 DIPHOSPHATE × 1 LAURIC ACID × 1 2-AMINO-VINYL-PHOSPHATE × 1 FERRICROCIN-IRON × 1 MYRISTIC ACID × 1	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	FHUA_ECOLI
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–725； UniProt 34–758 Author chain B； PDBConstruct 1–725； UniProt 34–758

Protein tonB

Escherichia coli

UniProt P94739

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Other combination	Heteromer	Protein 2 其他Polymer 1	Ferrichrome-iron receptor × 1 （P06971） ;3-deoxy-alpha-D-manno-oct-2-ulopyranosonic acid-(2-4)-[L-glycero-alpha-D-manno-heptopyranose-(1-5)]3-deoxy-alpha-D-manno-oct-2-ulopyranosonic acid-(2-6)-2-amino-2,3-dideoxy-alpha-D-glucoyranose-(1-6)-2-amino-2,3-dideoxy-alpha-D-glucoyranose ; × 1 PHOSPHATE ION × 1 3-HYDROXY-TETRADECANOIC ACID × 4 DIPHOSPHATE × 1 LAURIC ACID × 1 2-AMINO-VINYL-PHOSPHATE × 1 FERRICROCIN-IRON × 1	Consistent with protein count
2	Other combination	Heteromer	Protein 2 其他Polymer 1	Ferrichrome-iron receptor × 1 （P06971） ;3-deoxy-alpha-D-manno-oct-2-ulopyranosonic acid-(2-4)-[L-glycero-alpha-D-manno-heptopyranose-(1-5)]3-deoxy-alpha-D-manno-oct-2-ulopyranosonic acid-(2-6)-2-amino-2,3-dideoxy-alpha-D-glucoyranose-(1-6)-2-amino-2,3-dideoxy-alpha-D-glucoyranose ; × 1 PHOSPHATE ION × 1 3-HYDROXY-TETRADECANOIC ACID × 4 DIPHOSPHATE × 1 LAURIC ACID × 1 2-AMINO-VINYL-PHOSPHATE × 1 FERRICROCIN-IRON × 1 MYRISTIC ACID × 1	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	TONB_ECOLI
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain C； PDBConstruct 23–229； UniProt 33–239 Author chain D； PDBConstruct 23–229； UniProt 33–239

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	2grx
Deposition date deposition_date	2006-04-25
Structure title title	Crystal structure of TonB in complex with FhuA, E. coli outer membrane receptor for ferrichrome
Keywords keywords	BETA BARREL, OUTER MEMBRANE, HETEROCOMPLEX, INTER-PROTEIN BETA SHEET, PROTEIN-PROTEIN, METAL TRANSPORT; METAL TRANSPORT
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.

2grx__assembly_1__model_1

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

Download this curve (.dat)

2grx__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

2grx__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	28.18 Å
Rg (electron density)	27.64 Å
Total Rg	28.38 Å
Atom count	6295
Residues	780
Excluded volume	110990 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`2grx__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`2grx__assembly_2__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 (10)

Entity 1 Entity 1 polymer

Description description	Ferrichrome-iron receptor
Molecular weight formula_weight	80051.1 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	12533

AVEPKEDTITVTAAPAPQESAWGPAATIAARQSATGTKTDTPIQKVPQSISVVTAEEMALHQPKSVKEALSYTPGVSVGTRGASNTYDHLIIRGFAAEGQSQNNYLNGLKLQGNFYNDAVIDPYMLERAEIMRGPVSVLYGKSSPGGLLNMVSKRPTTEPLKEVQFKAGTDSLFQTGFDFSDSLDDDGVYSYRLTGLARSANAQQKGSEEQRYAIAPAFTWRPDDKTNFTFLSYFQNEPETGYYGWLPKEGTVEPLPNGKRLPTDFNEGAKNNTYSRNEKMVGYSFDHEFNDTFTVRQNLRFAENKTSQNSVYGYGVCSDPANAYSKQCAALAPADKGHYLARKYVVDDEKLQNFSVDTQLQSKFATGDIDHTLLTGVDFMRMRNDINAWFGYDDSVPLLNLYNPSSHHHHHHGSSVNTDFDFNAKDPANSGPYRILNKQKQTGVYVQDQAQWDKVLVTLGGRYDWADQESLNRVAGTTDKRDDKQFTWRGGVNYLFDNGVTPYFSYSESFEPSSQVGKDGNIFAPSKGKQYEVGVKYVPEDRPIVVTGAVYNLTKTNNLMADPEGSFFSVEGGEIRARGVEIEAKAALSASVNVVGSYTYTDAEYTTDTTYKGNTPAQVPKHMASLWADYTFFDGPLSGLTLGTGGRYTGSSYGDPANSFKVGSYTVVDALVRYDLARVGMAGSNVALHVNNLFDREYVASCFNTYGCFWGAERQVVATATFRF

Source Source

Source organism organism	Escherichia coli
NCBI taxonomy ID ncbi_taxonomy_id	562
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 polymer

Description description	Protein tonB
Molecular weight formula_weight	24973.6 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	C,D

GSSHHHHHHSSGLVPRGSHMSVHQVIELPAPAQPISVTMVTPADLEPPQAVQPPPEPVVEPEPEPEPIPEPPKEAPVVIEKPKPKPKPKPKPVKKVQEQPKRDVKPVESRPASPFENTAPARLTSSTATAATSKPVTSVASGPRALSRNQPQYPARAQALRIEGQVKVKFDVTPDGRVDNVQILSAKPANMFEREVKNAMRRWRYEPGKPGSGIVVNILFKINGTTEIQ

Source Source

Source organism organism	Escherichia coli
NCBI taxonomy ID ncbi_taxonomy_id	562
Host organism host_organism	Escherichia coli

Entity 3 Entity 3 branched

Description description	;3-deoxy-alpha-D-manno-oct-2-ulopyranosonic acid-(2-4)-[L-glycero-alpha-D-manno-heptopyranose-(1-5)]3-deoxy-alpha-D-manno-oct-2-ulopyranosonic acid-(2-6)-2-amino-2,3-dideoxy-alpha-D-glucoyranose-(1-6)-2-amino-2,3-dideoxy-alpha-D-glucoyranose ;
Molecular weight formula_weight	940.8 kDa
Source method src_method	man
Copy count entity_count	2

Entity 4 Entity 4 non-polymer

Description description	PHOSPHATE ION
Molecular weight formula_weight	95.0 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 5 Entity 5 non-polymer

Description description	3-HYDROXY-TETRADECANOIC ACID
Molecular weight formula_weight	244.4 kDa
Source method src_method	syn
Copy count entity_count	8

Entity 6 Entity 6 non-polymer

Description description	DIPHOSPHATE
Molecular weight formula_weight	173.9 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 7 Entity 7 non-polymer

Description description	LAURIC ACID
Molecular weight formula_weight	200.3 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 8 Entity 8 non-polymer

Description description	2-AMINO-VINYL-PHOSPHATE
Molecular weight formula_weight	139.0 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 9 Entity 9 non-polymer

Description description	FERRICROCIN-IRON
Molecular weight formula_weight	770.5 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 10 Entity 10 non-polymer

Description description	MYRISTIC ACID
Molecular weight formula_weight	228.4 kDa
Source method src_method	syn
Copy count entity_count	1

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6. Fold Classification (SCOP + CATH) 10 domains

SCOP 2.08 (4 domains)

Domain ID domain_id	d2grxa1
Class class	f — Membrane and cell surface proteins and peptides
Fold Fold fold	f.4 — Transmembrane beta-barrels
Superfamily Superfamily superfamily	f.4.3 — Porins
Family Family family	f.4.3.3 — Ligand-gated protein channel

Domain ID domain_id	d2grxb1
Class class	f — Membrane and cell surface proteins and peptides
Fold Fold fold	f.4 — Transmembrane beta-barrels
Superfamily Superfamily superfamily	f.4.3 — Porins
Family Family family	f.4.3.3 — Ligand-gated protein channel

Domain ID domain_id	d2grxc1
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.212 — TolA/TonB C-terminal domain
Superfamily Superfamily superfamily	d.212.1 — TolA/TonB C-terminal domain
Family Family family	d.212.1.2 — TonB

Domain ID domain_id	d2grxd1
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.212 — TolA/TonB C-terminal domain
Superfamily Superfamily superfamily	d.212.1 — TolA/TonB C-terminal domain
Family Family family	d.212.1.2 — TonB

CATH v4.4 (6 domains)

Domain ID domain_id	2grxA01
Class class	2 — Mainly Beta
Architecture architecture	170 — Beta Complex
Topology topology	130 — Ferric Hydroxamate Uptake Protein; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — TonB-dependent receptor, plug domain

Domain ID domain_id	2grxA02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	170 — Maltoporin; Chain A
Homologous superfamily homologous superfamily	20 — TonB-dependent receptor, beta-barrel domain

Domain ID domain_id	2grxB01
Class class	2 — Mainly Beta
Architecture architecture	170 — Beta Complex
Topology topology	130 — Ferric Hydroxamate Uptake Protein; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — TonB-dependent receptor, plug domain

Domain ID domain_id	2grxB02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	170 — Maltoporin; Chain A
Homologous superfamily homologous superfamily	20 — TonB-dependent receptor, beta-barrel domain

Domain ID domain_id	2grxC00
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	2420 — TolA/TonB C-terminal domain
Homologous superfamily homologous superfamily	10 — TonB

Domain ID domain_id	2grxD00
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	2420 — TolA/TonB C-terminal domain
Homologous superfamily homologous superfamily	10 — TonB

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Unit-cell length a length_a	234.320 Å
Unit-cell length b length_b	91.840 Å
Unit-cell length c length_c	138.510 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	118.86 °
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	3.300 Å
Low-resolution limit resolution_low	50.000 Å
R factor r_factor	0.2990
R_work r_work	0.2840
R_free r_free	0.3290

Crystal structure of TonB in complex with FhuA, E. coli outer membrane receptor for ferrichrome

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

Ferrichrome-iron receptor

State in the Current Structure

Other States of the Same Protein in the Database

Protein tonB

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

2grx__assembly_1__model_1

2grx__assembly_1__model_1 | I(q)

2grx__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 (10)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 branched

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 non-polymer

Entity 8 Entity 8 non-polymer

Entity 9 Entity 9 non-polymer

Entity 10 Entity 10 non-polymer

6. Fold Classification (SCOP + CATH) 10 domains

SCOP 2.08 (4 domains)

CATH v4.4 (6 domains)

7. Citations (1)

Crystal structure of TonB in complex with FhuA, E. coli outer membrane receptor for ferrichrome

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

Ferrichrome-iron receptor

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Protein tonB

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

2grx__assembly_1__model_1

2grx__assembly_1__model_1 | I(q)

2grx__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 (10)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 branched

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 non-polymer

Entity 8 Entity 8 non-polymer

Entity 9 Entity 9 non-polymer

Entity 10 Entity 10 non-polymer

6. Fold Classification (SCOP + CATH) 10 domains

SCOP 2.08 (4 domains)

CATH v4.4 (6 domains)

7. Citations (1)