6c97

Crystal structure of FcRn at pH3

Method: X-RAY DIFFRACTION

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

IgG receptor FcRn large subunit p51

Homo sapiens

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	Beta-2-microglobulin × 1 （P61769） GLYCEROL × 3 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 2	Beta-2-microglobulin × 1 （P61769） water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	FCGRN_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–274； UniProt 24–297 Author chain C； PDBConstruct 1–274； UniProt 24–297

Beta-2-microglobulin

Homo sapiens

UniProt P61769

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	IgG receptor FcRn large subunit p51 × 1 （P55899） GLYCEROL × 3 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 2	IgG receptor FcRn large subunit p51 × 1 （P55899） water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	B2MG_HUMAN
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 1–99； UniProt 21–119 Author chain D； PDBConstruct 1–99； UniProt 21–119

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	6c97
Deposition date deposition_date	2018-01-25
Structure title title	Crystal structure of FcRn at pH3
Keywords keywords	Neonatal Fc Receptor, FcRn, Inhibitor, beta 2 microglobulin, b2m, IMMUNE SYSTEM; IMMUNE SYSTEM
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.

6c97__assembly_1__model_1

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

Download this curve (.dat)

6c97__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

6c97__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	23.56 Å
Rg (electron density)	22.55 Å
Total Rg	23.43 Å
Atom count	2883
Residues	364
Excluded volume	50601 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`6c97__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`6c97__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 (4)

Entity 1 Entity 1 polymer

Description description	IgG receptor FcRn large subunit p51
Molecular weight formula_weight	30408.1 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,C
Atom count atom_count	6266

AESHLSLLYHLTAVSSPAPGTPAFWVSGWLGPQQYLSYNSLRGEAEPCGAWVWENQVSWYWEKETTDLRIKEKLFLEAFKALGGKGPYTLQGLLGCELGPDNTSVPTAKFALNGEEFMNFDLKQGTWGGDWPEALAISQRWQQQDKAANKELTFLLFSCPHRLREHLERGRGNLEWKEPPSMRLKARPSSPGFSVLTCSAFSFYPPELQLRFLRNGLAAGTGQGDFGPNSDGSFHASSSLTVKSGDEHHYCCIVQHAGLAQPLRVELESPAKSS

Source Source

Source organism organism	Homo sapiens
Common name common_name	Human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Trichoplusia ni

Entity 2 Entity 2 polymer

Description description	Beta-2-microglobulin
Molecular weight formula_weight	11748.2 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

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

IQRTPKIQVYSRHPAENGKSNFLNCYVSGFHPSDIEVDLLKNGERIEKVEHSDLSFSKDWSFYLLYYTEFTPTEKDEYACRVNHVTLSQPKIVKWDRDM

Source Source

Source organism organism	Homo sapiens
Common name common_name	Human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Trichoplusia ni

Entity 3 Entity 3 non-polymer

Description description	GLYCEROL
Molecular weight formula_weight	92.1 kDa
Source method src_method	syn
Copy count entity_count	3

Entity 4 Entity 4 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	486

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6. Fold Classification (SCOP + CATH) 12 domains

SCOP 2.08 (6 domains)

Domain ID domain_id	d6c97a1
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.19 — MHC antigen-recognition domain
Superfamily Superfamily superfamily	d.19.1 — MHC antigen-recognition domain
Family Family family	d.19.1.0 — automated matches

Domain ID domain_id	d6c97a2
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.0 — automated matches

Domain ID domain_id	d6c97b_
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.2 — C1 set domains (antibody constant domain-like)

Domain ID domain_id	d6c97c1
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.19 — MHC antigen-recognition domain
Superfamily Superfamily superfamily	d.19.1 — MHC antigen-recognition domain
Family Family family	d.19.1.0 — automated matches

Domain ID domain_id	d6c97c2
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.0 — automated matches

Domain ID domain_id	d6c97d_
Class class	b — All beta proteins
Fold Fold fold	b.1 — Immunoglobulin-like beta-sandwich
Superfamily Superfamily superfamily	b.1.1 — Immunoglobulin
Family Family family	b.1.1.2 — C1 set domains (antibody constant domain-like)

CATH v4.4 (6 domains)

Domain ID domain_id	6c97A01
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	500 — Murine Class I Major Histocompatibility Complex, H2-DB; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — MHC class I-like antigen recognition-like

Domain ID domain_id	6c97A02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	6c97B00
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	6c97C01
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	500 — Murine Class I Major Histocompatibility Complex, H2-DB; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — MHC class I-like antigen recognition-like

Domain ID domain_id	6c97C02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	6c97D00
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

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Unit-cell length a length_a	42.100 Å
Unit-cell length b length_b	76.250 Å
Unit-cell length c length_c	140.150 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	93.75 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	4

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

Resolution resolution	2.000 Å
Low-resolution limit resolution_low	46.616 Å
R factor r_factor	0.1756
R_work r_work	0.1739
R_free r_free	0.2102

Crystal structure of FcRn at pH3

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

IgG receptor FcRn large subunit p51

State in the Current Structure

Other States of the Same Protein in the Database

Beta-2-microglobulin

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

6c97__assembly_1__model_1

6c97__assembly_1__model_1 | I(q)

6c97__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 polymer

Polymer Polymer

Source Source

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 (1)

Crystal structure of FcRn at pH3

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

IgG receptor FcRn large subunit p51

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Beta-2-microglobulin

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

6c97__assembly_1__model_1

6c97__assembly_1__model_1 | I(q)

6c97__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 polymer

Polymer Polymer

Source Source

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 (1)