2ice

CRIg bound to C3c

Method: X-RAY DIFFRACTION

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

Complement C3 beta chain

OrganismNot specified

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Other combination	Heteromer	Protein 4 其他Polymer 1	V-set and immunoglobulin domain-containing protein 4 × 1 （Q9Y279） 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 1 CALCIUM ION × 1	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 4	V-set and immunoglobulin domain-containing protein 4 × 1 （Q9Y279） CALCIUM ION × 1	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	CO3_HUMAN
Isoform	—
PDB entities	1, 2, 3
Chains and sequence ranges	Author chain A； PDBConstruct 1–642； UniProt 23–664 Author chain D； PDBConstruct 1–642； UniProt 23–664 Author chain B； PDBConstruct 1–206； UniProt 749–954 Author chain E； PDBConstruct 1–206； UniProt 749–954 Author chain C； PDBConstruct 1–343； UniProt 1321–1663 Author chain F； PDBConstruct 1–343； UniProt 1321–1663

V-set and immunoglobulin domain-containing protein 4

Homo sapiens

UniProt Q9Y279

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Other combination	Heteromer	Protein 4 其他Polymer 1	Complement C3 beta chain × 1 （P01024） Complement C3 alpha chain × 1 （P01024） Complement C3 alpha chain × 1 （P01024） 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose × 1 CALCIUM ION × 1	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 4	Complement C3 beta chain × 1 （P01024） Complement C3 alpha chain × 1 （P01024） Complement C3 alpha chain × 1 （P01024） CALCIUM ION × 1	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	VSIG4_HUMAN
Isoform	—
PDB entities	4
Chains and sequence ranges	Author chain S； PDBConstruct 1–119； UniProt 19–137 Author chain T； PDBConstruct 1–119； UniProt 19–137

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	2ice
Deposition date deposition_date	2006-09-12
Structure title title	CRIg bound to C3c
Keywords keywords	Alternative Pathway, Complement, C3, CRIg, Complement Receptor, 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.

2ice__assembly_1__model_1

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

Download this curve (.dat)

2ice__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

2ice__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	40.70 Å
Rg (electron density)	40.41 Å
Total Rg	40.60 Å
Atom count	9874
Residues	1240
Excluded volume	176410 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`2ice__assembly_1__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`2ice__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 (6)

Entity 1 Entity 1 polymer

Description description	Complement C3 beta chain
Molecular weight formula_weight	71170.1 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,D
Atom count atom_count	19619

SPMYSIITPNILRLESEETMVLEAHDAQGDVPVTVTVHDFPGKKLVLSSEKTVLTPATNHMGNVTFTIPANREFKSEKGRNKFVTVQATFGTQVVEKVVLVSLQSGYLFIQTDKTIYTPGSTVLYRIFTVNHKLLPVGRTVMVNIENPEGIPVKQDSLSSQNQLGVLPLSWDIPELVNMGQWKIRAYYENSPQQVFSTEFEVKEYVLPSFEVIVEPTEKFYYIYNEKGLEVTITARFLYGKKVEGTAFVIFGIQDGEQRISLPESLKRIPIEDGSGEVVLSRKVLLDGVQNLRAEDLVGKSLYVSATVILHSGSDMVQAERSGIPIVTSPYQIHFTKTPKYFKPGMPFDLMVFVTNPDGSPAYRVPVAVQGEDTVQSLTQGDGVAKLSINTHPSQKPLSITVRTKKQELSEAEQATRTMQALPYSTVGNSNNYLHLSVLRTELRPGETLNVNFLLRMDRAHEAKIRYYTYLIMNKGRLLKAGRQVREPGQDLVVLPLSITTDFIPSFRLVAYYTLIGASGQREVVADSVWVDVKDSCVGSLVVKSGQSEDRQPVPGQQMTLKIEGDHGARVVLVAVDKGVFVLNKKNKLTQSKIWDVVEKADIGCTPGSGKDYAGVFSDAGLTFTSSSGQQTAQRAELQCPQ

Entity 2 Entity 2 polymer

Description description	Complement C3 alpha chain
Molecular weight formula_weight	23621.2 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

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

SNLDEDIIAEENIVSRSEFPESWLWNVEDLKEPPKNGISTKLMNIFLKDSITTWEILAVSMSDKKGICVADPFEVTVMQDFFIDLRLPYSVVRNEQVEIRAVLYNYRQNQELKVRVELLHNPAFCSLATTKRRHQQTVTIPPKSSLSVPYVIVPLKTGLQEVEVKAAVYHHFISDGVRKSLKVVPEGIRMNKTVAVRTLDPERLGR

Entity 3 Entity 3 polymer

Description description	Complement C3 alpha chain
Molecular weight formula_weight	39537.4 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

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

SEETKENEGFTVTAEGKGQGTLSVVTMYHAKAKDQLTCNKFDLKVTIKPAPETEKRPQDAKNTMILEICTRYRGDQDATMSILDISMMTGFAPDTDDLKQLANGVDRYISKYELDKAFSDRNTLIIYLDKVSHSEDDCLAFKVHQYFNVELIQPGAVKVYAYYNLEESCTRFYHPEKEDGKLNKLCRDELCRCAEENCFIQKSDDKVTLEERLDKACEPGVDYVYKTRLVKVQLSNDFDEYIMAIEQTIKSGSDEVQVGQQRTFISPIKCREALKLEEKKHYLMWGLSSDFWGEKPNLSYIIGKDTWVEHWPEEDECQDEENQKQCQDLGAFTESMVVFGCPN

Entity 4 Entity 4 polymer

Description description	V-set and immunoglobulin domain-containing protein 4
Molecular weight formula_weight	13501.2 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	S,T

GRPILEVPESVTGPWKGDVNLPCTYDPLQGYTQVLVKWLVQRGSDPVTIFLRDSSGDHIQQAKYQGRLHVSHKVPGDVSLQLSTLEMDDRSHYTCEVTWQTPDGNQVVRDKITELRVQK

Source Source

Source organism organism	Homo sapiens
Common name common_name	human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Escherichia coli

Entity 5 Entity 5 branched

Description description	2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
Molecular weight formula_weight	424.4 kDa
Source method src_method	man
Copy count entity_count	1

Entity 6 Entity 6 non-polymer

Description description	CALCIUM ION
Molecular weight formula_weight	40.1 kDa
Source method src_method	syn
Copy count entity_count	2

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6. Fold Classification (SCOP + CATH) 22 domains

CATH v4.4 (22 domains)

Domain ID domain_id	2iceA01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	1930 — Macroglobulin (MG2) domain

Domain ID domain_id	2iceA02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	1930 — Macroglobulin (MG2) domain

Domain ID domain_id	2iceA03
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	1940 —

Domain ID domain_id	2iceA04
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	2iceA05
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	1930 — Macroglobulin (MG2) domain

Domain ID domain_id	2iceA06
Class class	6 — Special
Architecture architecture	20 — Other non-globular
Topology topology	50 — N-terminal domain of TfIIb
Homologous superfamily homologous superfamily	160 —

Domain ID domain_id	2iceB01
Class class	2 — Mainly Beta
Architecture architecture	20 — Single Sheet
Topology topology	130 — S-adenosyl-L-methionine-dependent methyltransferases
Homologous superfamily homologous superfamily	20 —

Domain ID domain_id	2iceB02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	2iceC01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	690 — Alpha-macroglobulin, receptor-binding domain

Domain ID domain_id	2iceC02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	120 —

Domain ID domain_id	2iceD01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	1930 — Macroglobulin (MG2) domain

Domain ID domain_id	2iceD02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	1930 — Macroglobulin (MG2) domain

Domain ID domain_id	2iceD03
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	1940 —

Domain ID domain_id	2iceD04
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	2iceD05
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	1930 — Macroglobulin (MG2) domain

Domain ID domain_id	2iceD06
Class class	6 — Special
Architecture architecture	20 — Other non-globular
Topology topology	50 — N-terminal domain of TfIIb
Homologous superfamily homologous superfamily	160 —

Domain ID domain_id	2iceE01
Class class	2 — Mainly Beta
Architecture architecture	20 — Single Sheet
Topology topology	130 — S-adenosyl-L-methionine-dependent methyltransferases
Homologous superfamily homologous superfamily	20 —

Domain ID domain_id	2iceE02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	2iceF01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	690 — Alpha-macroglobulin, receptor-binding domain

Domain ID domain_id	2iceF02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	120 —

Domain ID domain_id	2iceS00
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	2iceT00
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	384.936 Å
Unit-cell length b length_b	65.213 Å
Unit-cell length c length_c	147.676 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	102.91 °
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	3.100 Å
Low-resolution limit resolution_low	20.000 Å
R factor r_factor	0.2390
R_work r_work	0.2360
R_free r_free	0.2950

CRIg bound to C3c

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

Complement C3 beta chain

State in the Current Structure

Other States of the Same Protein in the Database

V-set and immunoglobulin domain-containing protein 4

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

2ice__assembly_1__model_1

2ice__assembly_1__model_1 | I(q)

2ice__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 (6)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 polymer

Polymer Polymer

Entity 4 Entity 4 polymer

Polymer Polymer

Source Source

Entity 5 Entity 5 branched

Entity 6 Entity 6 non-polymer

6. Fold Classification (SCOP + CATH) 22 domains

CATH v4.4 (22 domains)

7. Citations (1)

CRIg bound to C3c

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

Complement C3 beta chain

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

V-set and immunoglobulin domain-containing protein 4

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

2ice__assembly_1__model_1

2ice__assembly_1__model_1 | I(q)

2ice__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 (6)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 polymer

Polymer Polymer

Entity 4 Entity 4 polymer

Polymer Polymer

Source Source

Entity 5 Entity 5 branched

Entity 6 Entity 6 non-polymer

6. Fold Classification (SCOP + CATH) 22 domains

CATH v4.4 (22 domains)

7. Citations (1)