7kn3

Crystal structure of SARS-CoV-2 spike protein receptor-binding domain complexed with a pre-pandemic antibody S-B8 Fab

Method: X-RAY DIFFRACTION

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

Spike protein S1

Severe acute respiratory syndrome coronavirus 2

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 3	S-B8 Fab heavy chain × 1 S-B8 Fab light chain × 1 2-acetamido-2-deoxy-beta-D-glucopyranose × 1 1,2-ETHANEDIOL × 4 SULFATE ION × 2 TRIETHYLENE GLYCOL × 2 water × 3	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 3	S-B8 Fab heavy chain × 1 S-B8 Fab light chain × 1 2-acetamido-2-deoxy-beta-D-glucopyranose × 1 1,2-ETHANEDIOL × 4 water × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	SPIKE_SARS2
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–223； UniProt 319–541 Author chain B； PDBConstruct 1–223； UniProt 319–541

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	7kn3
Deposition date deposition_date	2020-11-04
Structure title title	Crystal structure of SARS-CoV-2 spike protein receptor-binding domain complexed with a pre-pandemic antibody S-B8 Fab
Keywords keywords	SARS-CoV-2, Antibody, Spike, Coronavirus, COVID-19, IMMUNE SYSTEM, VIRAL PROTEIN-IMMUNE SYSTEM complex, phage display, pre-pandemic; VIRAL PROTEIN/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.

7kn3__assembly_1__model_1

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

Download this curve (.dat)

7kn3__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

7kn3__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	32.65 Å
Rg (electron density)	32.70 Å
Total Rg	33.21 Å
Atom count	4890
Residues	634
Excluded volume	86326 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`7kn3__assembly_1__model_1`	trimeric （3）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`7kn3__assembly_2__model_1`	trimeric （3）	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 (8)

Entity 1 Entity 1 polymer

Description description	Spike protein S1
Molecular weight formula_weight	26095.3 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	10195

RVQPTESIVRFPNITNLCPFGEVFNATRFASVYAWNRKRISNCVADYSVLYNSASFSTFKCYGVSPTKLNDLCFTNVYADSFVIRGDEVRQIAPGQTGKIADYNYKLPDDFTGCVIAWNSNNLDSKVGGNYNYLYRLFRKSNLKPFERDISTEIYQAGSTPCNGVEGFNCYFPLQSYGFQPTNGVGYQPYRVVVLSFELLHAPATVCGPKKSTNLVKNKCVNFSGHHHHHH

Source Source

Source organism organism	Severe acute respiratory syndrome coronavirus 2
Common name common_name	2019-nCoV
NCBI taxonomy ID ncbi_taxonomy_id	2697049
Host organism host_organism	Trichoplusia ni

Entity 2 Entity 2 polymer

Description description	S-B8 Fab heavy chain
Molecular weight formula_weight	23225.9 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	H,M

QVQLVQSGGGLIQPGGSLRLSCAASGFTVSLSHMNWVRQAPGKGLEWVSITYGDGNSDYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAREYYYGMDVWGQGTTVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSC

Source Source

Source organism organism	Homo sapiens
Common name common_name	human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Mus musculus

Entity 3 Entity 3 polymer

Description description	S-B8 Fab light chain
Molecular weight formula_weight	24271.9 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	L,N

DIVMTQSPDSLAVSLGERATINCKSSQSVLYSSNNKNYLAWYQQKPGQPPKLLIYWASTRESGVPDRFSGSGSGTDFTLTISSLQAEDVAVYYCQQYYSLPLTFGGGTKLEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGECS

Source Source

Source organism organism	Homo sapiens
Common name common_name	human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Mus musculus

Entity 4 Entity 4 non-polymer

Description description	2-acetamido-2-deoxy-beta-D-glucopyranose
Molecular weight formula_weight	221.2 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 5 Entity 5 non-polymer

Description description	1,2-ETHANEDIOL
Molecular weight formula_weight	62.1 kDa
Source method src_method	syn
Copy count entity_count	8

Entity 6 Entity 6 non-polymer

Description description	SULFATE ION
Molecular weight formula_weight	96.1 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 7 Entity 7 non-polymer

Description description	TRIETHYLENE GLYCOL
Molecular weight formula_weight	150.2 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 8 Entity 8 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	441

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6. Fold Classification (SCOP + CATH) 8 domains

CATH v4.4 (8 domains)

Domain ID domain_id	7kn3H01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	7kn3H02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	7kn3L01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	7kn3L02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	7kn3M01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	7kn3M02
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	7kn3N01
Class class	2 — Mainly Beta
Architecture architecture	60 — Sandwich
Topology topology	40 — Immunoglobulin-like
Homologous superfamily homologous superfamily	10 — Immunoglobulins

Domain ID domain_id	7kn3N02
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	191.564 Å
Unit-cell length b length_b	191.564 Å
Unit-cell length c length_c	117.371 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.00 °
Unit-cell angle γ angle_gamma	120.00 °
Molecules per unit cell Z z_pdb	18

Space group space_group	H 3
Space-group number int_tables_number	146
Crystal system crystal_system	trigonal

Resolution resolution	2.251 Å
Low-resolution limit resolution_low	47.908 Å
R factor r_factor	0.1881
R_work r_work	0.1863
R_free r_free	0.2219

Crystal structure of SARS-CoV-2 spike protein receptor-binding domain complexed with a pre-pandemic antibody S-B8 Fab

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

Spike protein S1

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

7kn3__assembly_1__model_1

7kn3__assembly_1__model_1 | I(q)

7kn3__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 (8)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 polymer

Polymer Polymer

Source Source

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 water

6. Fold Classification (SCOP + CATH) 8 domains

CATH v4.4 (8 domains)

7. Citations (1)

Crystal structure of SARS-CoV-2 spike protein receptor-binding domain complexed with a pre-pandemic antibody S-B8 Fab

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

Spike protein S1

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

7kn3__assembly_1__model_1

7kn3__assembly_1__model_1 | I(q)

7kn3__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 (8)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 polymer

Polymer Polymer

Source Source

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 water

6. Fold Classification (SCOP + CATH) 8 domains

CATH v4.4 (8 domains)

7. Citations (1)