9on4

Crystal structure of Zn2+ bound Calprotectin variant I73K

Method: X-RAY DIFFRACTION

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

Protein S100-A8

Homo sapiens

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 4	Protein S100-A9 × 2 （P06702） CALCIUM ION × 6 ZINC ION × 2 water × 4	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 4	Protein S100-A9 × 2 （P06702） CALCIUM ION × 6 ZINC ION × 2 CHLORIDE ION × 2 MAGNESIUM ION × 1 water × 4	Consistent with protein count
3	Protein heterocomplex	Heteromer	Protein 4	Protein S100-A9 × 2 （P06702） CALCIUM ION × 7 ZINC ION × 2 water × 4	Consistent with protein count
4	Protein heterocomplex	Heteromer	Protein 4	Protein S100-A9 × 2 （P06702） CALCIUM ION × 6 ZINC ION × 2 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	S10A8_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–93； UniProt 1–93 Author chain C； PDBConstruct 1–93； UniProt 1–93 Author chain E； PDBConstruct 1–93； UniProt 1–93 Author chain G； PDBConstruct 1–93； UniProt 1–93 Author chain IA； PDBConstruct 1–93； UniProt 1–93 Author chain KA； PDBConstruct 1–93； UniProt 1–93 Author chain MA； PDBConstruct 1–93； UniProt 1–93 Author chain PA； PDBConstruct 1–93； UniProt 1–93

Protein S100-A9

Homo sapiens

UniProt P06702

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 4	Protein S100-A8 × 2 （P05109） CALCIUM ION × 6 ZINC ION × 2 water × 4	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 4	Protein S100-A8 × 2 （P05109） CALCIUM ION × 6 ZINC ION × 2 CHLORIDE ION × 2 MAGNESIUM ION × 1 water × 4	Consistent with protein count
3	Protein heterocomplex	Heteromer	Protein 4	Protein S100-A8 × 2 （P05109） CALCIUM ION × 7 ZINC ION × 2 water × 4	Consistent with protein count
4	Protein heterocomplex	Heteromer	Protein 4	Protein S100-A8 × 2 （P05109） CALCIUM ION × 6 ZINC ION × 2 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	S10A9_HUMAN
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 1–114； UniProt 1–114 Author chain D； PDBConstruct 1–114； UniProt 1–114 Author chain F； PDBConstruct 1–114； UniProt 1–114 Author chain H； PDBConstruct 1–114； UniProt 1–114 Author chain JA； PDBConstruct 1–114； UniProt 1–114 Author chain LA； PDBConstruct 1–114； UniProt 1–114 Author chain NA； PDBConstruct 1–114； UniProt 1–114 Author chain OA； PDBConstruct 1–114； UniProt 1–114

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	9on4
Deposition date deposition_date	2025-05-14
Last revision last_revision	2026-03-04
Structure title title	Crystal structure of Zn2+ bound Calprotectin variant I73K
Keywords keywords	EF-hand, calcium-binding, inflammation, innate immunity, METAL BINDING PROTEIN; METAL BINDING PROTEIN
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.

9on4__assembly_1__model_1

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

Download this curve (.dat)

9on4__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

9on4__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	21.66 Å
Rg (electron density)	20.46 Å
Total Rg	21.36 Å
Atom count	3115
Residues	390
Excluded volume	55623 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`9on4__assembly_1__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`9on4__assembly_2__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`9on4__assembly_3__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
4	1	`9on4__assembly_4__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 (7)

Entity 1 Entity 1 polymer

Description description	Protein S100-A8
Molecular weight formula_weight	10853.5 kDa
Mutation mutation	C42S, I73K
Source method src_method	man
Copy count entity_count	8

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,C,E,G,IA,KA,MA,PA
Atom count atom_count	13773

MLTELEKALNSIIDVYHKYSLIKGNFHAVYRDDLKKLLETESPQYIRKKGADVWFKELDINTDGAVNFQEFLKLVIKMGVAAHKKSHEESHKE

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 2 Entity 2 polymer

Description description	Protein S100-A9
Molecular weight formula_weight	13248.0 kDa
Mutation mutation	C3S
Source method src_method	man
Copy count entity_count	8

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B,D,F,H,JA,LA,NA,OA

MTSKMSQLERNIETIINTFHQYSVKLGHPDTLNQGEFKELVRKDLQNFLKKENKNEKVIEHIMEDLDTNADKQLSFEEFIMLMARLTWASHEKMHEGDEGPGHHHKPGLGEGTP

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 3 Entity 3 non-polymer

Description description	CALCIUM ION
Molecular weight formula_weight	40.1 kDa
Source method src_method	nat
Copy count entity_count	25

Entity 4 Entity 4 non-polymer

Description description	ZINC ION
Molecular weight formula_weight	65.4 kDa
Source method src_method	syn
Copy count entity_count	8

Entity 5 Entity 5 non-polymer

Description description	CHLORIDE ION
Molecular weight formula_weight	35.5 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 6 Entity 6 non-polymer

Description description	MAGNESIUM ION
Molecular weight formula_weight	24.3 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 7 Entity 7 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	1141

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Unit-cell length a length_a	106.480 Å
Unit-cell length b length_b	83.585 Å
Unit-cell length c length_c	109.685 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	97.74 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	16

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

Resolution resolution	1.660 Å
Low-resolution limit resolution_low	36.230 Å
R factor r_factor	0.1838
R_work r_work	0.1835
R_free r_free	0.2212

Crystal structure of Zn2+ bound Calprotectin variant I73K

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

Protein S100-A8

State in the Current Structure

Other States of the Same Protein in the Database

Protein S100-A9

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

9on4__assembly_1__model_1

9on4__assembly_1__model_1 | I(q)

9on4__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 (7)

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 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 water

7. Citations (2)

Crystal structure of Zn2+ bound Calprotectin variant I73K

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

Protein S100-A8

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 S100-A9

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

9on4__assembly_1__model_1

9on4__assembly_1__model_1 | I(q)

9on4__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 (7)

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 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 water

7. Citations (2)