SAXSdb — 2a1i

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

DNA excision repair protein ERCC-1

Homo sapiens

State in the Current Structure

Assembly	Oligomeric State	Construct	Mutations and Modifications	Ligands, Ions and Associated Components	Method and Experimental Conditions	Structure Quality
1	Protein monomer Monomer Protein × 1 PDB declaration: monomeric（1） Consistent with protein copy count	Chain A； UniProt 96–227	Fragment：CENTRAL DOMAIN	HG MERCURY (II) ION × 1	X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, SITTING DROP；pH 6.5；295 K；MES, PEG 5000 MME, GLYCEROL, pH 6.5, VAPOR DIFFUSION, SITTING DROP,temperature 295K	Resolution 1.90 Å R-free 0.248

Other States of the Same Protein in the Database

Each row is a biological assembly of the same UniProt protein in another PDB entry. The “Difference from current entry” column identifies evidence-level differences; no tag means the currently parsed fields agree.

Other PDB	Difference from Current Entry 2A1I	Assembly / Oligomeric State	Construct	Mutations and Modifications	Ligands, Ions and Non-polymers	Method and Experimental Conditions	Structure Quality
1Z00 Solution structure of the C-terminal domain of ERCC1 complexed with the C-terminal domain of XPF Deposited 2005-03-01	Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain A 220–297（78 aa） Fragment：C-TERMINAL DOMAIN	Not recorded	No recorded non-water small molecule	SOLUTION NMR NMR measurement conditions pH 7；295.5 K；Ionic strength (raw mmCIF value) 50mM phosphate, 100mM NaCl；Pressure 1 NMR sample composition 1.5mM ERCC1-XPF U-15N,13C; 50mM phosphate buffer NA: 92% H2O, 8% D2O \| 92% H2O, 8% D2O NMR sample composition 1mM ERCC1-XPF U-15N; 50mM phosphate buffer NA: 92% H2O, 8% D2O \| 92% H2O, 8% D2O	Resolution not provided
2A1J Crystal Structure of the Complex between the C-Terminal Domains of Human XPF and ERCC1 Deposited 2005-06-20	Different construct Different oligomeric state Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain B 220–296（77 aa） Fragment：C-terminal domain	Not recorded	HG MERCURY (II) ION × 1	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 4.5；295 K；Sodium Citrate, Ammonium Sulfate, Sodium Chloride, pH 4.5, VAPOR DIFFUSION, HANGING DROP, temperature 295K	Resolution 2.70 Å R-free 0.275
2A1J Crystal Structure of the Complex between the C-Terminal Domains of Human XPF and ERCC1 Deposited 2005-06-20	Different construct Different oligomeric state Different ligand/ion Different experimental conditions Different structure-quality metrics	Assembly 2 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain B 220–296（77 aa） Fragment：C-terminal domain	Not recorded	HG MERCURY (II) ION × 2	X-RAY DIFFRACTION X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 4.5；295 K；Sodium Citrate, Ammonium Sulfate, Sodium Chloride, pH 4.5, VAPOR DIFFUSION, HANGING DROP, temperature 295K	Resolution 2.70 Å R-free 0.275
2JNW Solution structure of a ERCC1-XPA heterodimer Deposited 2007-02-07	Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain A 96–214（119 aa） Fragment：Central domain, residues 96-214	Not recorded	No recorded non-water small molecule	SOLUTION NMR NMR measurement conditions pH 7.2；295 K；Ionic strength (raw mmCIF value) 0.05；Pressure ambient NMR sample composition 0.25 mM [U-100% 13C; U-100% 15N] ERCC1, 20 mM Tris-HCl pH 7.2, 50 mM NaCl, 2 mM beta-mercaptoethanol, 0.1 mM EDTA, 90% H2O, 10% D2O \| 90% H2O/10% D2O NMR sample composition 0.25 mM [U-100% 15N, 100% 2H] ERCC1, 20 mM Tris-HCl pH 7.2, 50 mM NaCl, 2 mM beta-mercaptoethanol, 0.1 mM EDTA, 90% H2O, 10% D2O \| 90% H2O/10% D2O	Resolution not provided
2JPD Solution structure of the ERCC1 central domain Deposited 2007-05-06	Different construct Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein monomer Monomer；Protein × 1 PDB declaration: monomeric	Chain A 96–219（124 aa） Fragment：residues 96-219	Not recorded	No recorded non-water small molecule	SOLUTION NMR NMR measurement conditions pH 5.5；290 K；Ionic strength (raw mmCIF value) 0.2；Pressure ambient NMR sample composition 50 mM sodium phosphate, 100 mM sodium chloride, 95% H2O/5% D2O \| 95% H2O/5% D2O	Resolution not provided
2MUT Solution structure of the F231L mutant ERCC1-XPF dimerization region Deposited 2014-09-17	Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain A 220–297（78 aa） Fragment：UNP residues 220-297	Mutation：F231L	No recorded non-water small molecule	SOLUTION NMR NMR measurement conditions pH 7；290 K；Ionic strength (raw mmCIF value) 250；Pressure ambient NMR sample composition 0.4 mM [U-100% 13C; U-100% 15N] protein_1, 0.4 mM [U-100% 13C; U-100% 15N] protein_2, 8 % D2O, 50 mM sodium phosphate, 100 mM sodium chloride, 92% H2O/8% D2O \| 92% H2O/8% D2O	Resolution not provided
6SXA XPF-ERCC1 Cryo-EM Structure, Apo-form Deposited 2019-09-25	Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric	Chain G 1–297（297 aa）	Not recorded	No recorded non-water small molecule	ELECTRON MICROSCOPY cryo-EM buffer pH 7.8；20 mM HEPES pH 7.8, 150 mM NaCl, 1 mM TCEP, 0.01% CHAPS cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.60 Å
6SXB XPF-ERCC1 Cryo-EM Structure, DNA-Bound form Deposited 2019-09-25	Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein–DNA Heteromer；Protein × 2 PDB declaration: tetrameric	Chain G 1–297（297 aa）	Not recorded	No recorded non-water small molecule	ELECTRON MICROSCOPY cryo-EM buffer pH 7.8；20 mM HEPES pH 7.8, 150 mM NaCl, 1 mM TCEP, 0.01% CHAPS cryo-EM vitrification conditions Cryogen ETHANE	Resolution 7.90 Å
9PCP NER dual incision complex - NoG Deposited 2025-06-28	Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein–DNA Heteromer；Protein × 13 PDB declaration: 15-meric	Chain R 1–297（297 aa）	Not recorded	SF4 IRON/SULFUR CLUSTER × 1 ZN ZINC ION × 6 CA CALCIUM ION × 2	ELECTRON MICROSCOPY cryo-EM buffer pH 7.9 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 4.30 Å
9PD3 NER dual incision complex - DuIS Deposited 2025-06-30	Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein–DNA Heteromer；Protein × 15 PDB declaration: 17-meric	Chain R 1–295（295 aa）	Not recorded	SF4 IRON/SULFUR CLUSTER × 1 ZN ZINC ION × 7	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.30 Å
9PD4 NER dual incision complex - DuIM Deposited 2025-06-30	Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein–DNA Heteromer；Protein × 14 PDB declaration: hexadecameric	Chain R 1–295（295 aa）	Not recorded	SF4 IRON/SULFUR CLUSTER × 1 ZN ZINC ION × 7	ELECTRON MICROSCOPY cryo-EM buffer pH 8 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.40 Å
9QEC Cryo-EM structure of the XPF-ERCC1-XPA complex Deposited 2025-03-08	Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 3 PDB declaration: trimeric	Chain B 1–297（297 aa）	Not recorded	No recorded non-water small molecule	ELECTRON MICROSCOPY cryo-EM buffer pH 7.9 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 2.90 Å
9QED Cryo-EM structure of the XPF-ERCC1-SLX4(330-555)-SLX4IP complex Deposited 2025-03-09	Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein heterocomplex Heteromer；Protein × 4 PDB declaration: tetrameric	Chain B 1–297（297 aa）	Not recorded	No recorded non-water small molecule	ELECTRON MICROSCOPY cryo-EM buffer pH 7.9 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.20 Å
9QEE Cryo-EM structure of a DNA-bound XPF-ERCC1-SLX4(330-555)-SLX4IP complex Deposited 2025-03-09	Different construct Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics	Assembly 1 Protein–DNA Heteromer；Protein × 4 PDB declaration: hexameric	Chain B 1–297（297 aa）	Not recorded	MN MANGANESE (II) ION × 2	ELECTRON MICROSCOPY cryo-EM buffer pH 7.9 cryo-EM vitrification conditions Cryogen ETHANE	Resolution 3.40 Å

13 other PDB entries and 14 assemblies. Open the comparison page and filter oligomeric states

View Construct and Data Evidence

UniProt name	ERCC1_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 15–146； UniProt 96–227

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	2a1i
Deposition date deposition_date	2005-06-20
Structure title title	Crystal Structure of the Central Domain of Human ERCC1
Keywords keywords	ERCC1, XPF, NER, central domain, DNA repair, endonuclease, DNA BINDING PROTEIN; DNA BINDING PROTEIN
Experimental Method method	X-RAY DIFFRACTION

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3. SAXS Parameters (CRYSOL theoretical calculation) 3. SAXS Parameters (CRYSOL)

Radius of gyration Rg (Guinier) rg_guinier	16.36 Å
Radius of gyration Rg (electron density) rg_electron	15.69 Å
Forward intensity I(0) i0	4263950.00
Molecular weight molecular_weight	14940.0 kDa
Excluded volume excluded_volume	18800 Å³
Envelope volume envelope_volume	22271 Å³
Hydration-shell volume shell_volume	12625 Å³
Envelope diameter envelope_diameter	65.0 Å
Shell Rg shell_rg	21.17 Å
Envelope Rg envelope_rg	16.89 Å
Shape Rg shape_rg	15.70 Å
Total Rg total_rg	16.79 Å
Total atoms total_atoms	1040
Residues n_residues	129
Spherical-harmonic order n_harmonics	20
q range q_range	— – 0.5000 Å⁻¹
Data points n_points	101
Shell type shell_type	directional
Solvent electron density solvent_density	0.3340 e/Å³
Shell contrast contrast_shell	0.0300 e/Å³
CRYSOL version crysol_version	4.1.3

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4. P(r) Distance Distribution (GNOM inversion) 4. P(r) Analysis (GNOM)

Maximum dimension Dmax dmax	42.5 Å
Rg (real space) rg_real	15.25 Å
Rg uncertainty (real space) rg_real_error	0.05 Å
I(0) (real space) i0_real	4.0430e+06
I(0) uncertainty (real space) i0_real_error	3.3140e+04
Rg (reciprocal space) rg_reciprocal	16.46 Å
I(0) (reciprocal space) i0_reciprocal	4264000.0000
Solution quality estimate total_estimate	0.6860
Solution quality rating solution_quality	REASONABLE a REASONABLE solution
P(r) peaks n_peaks	1
Primary peak position r_peak_primary	18.6 Å
Skewness Skewness skewness	0.182
Kurtosis Kurtosis kurtosis	-0.384
Angular range angular_range	— – 0.4850 Å⁻¹
Current regularization parameter α current_alpha	2.8420
Highest regularization parameter α highest_alpha	560600.0000
Real-space data points n_real_points	79
GNOM version gnom_version	4.1.3
Quality Criteria quality_criteria	AN1: 0.009; Oscil: 0.989; Stabil: 0.986; Sysdev: 0.000; Positv: 1.000; Valcen: 0.993; Smooth: 0.000

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5. Crystallography and Experiment 5. Crystallography & Experiment

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6. Entities and Polymers Entities & Polymers (3)

Entity 1 Entity 1 polymer

Description description	DNA excision repair protein ERCC-1
Molecular weight formula_weight	16679.2 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A
Atom count atom_count	1170

MGSSHHHHHHSQDPAKSNSIIVSPRQRGNPVLKFVRNVPWEFGDVIPDYVLGQSTCALFLSLRYHNLHPDYIHGRLQSLGKNFALRVLLVQVDVKDPQQALKELAKMCILADCTLILAWSPEEAGRYLETYKAYEQKPADLLMEKL

来源 Source

来源生物 organism	Homo sapiens
通用名 common_name	human
NCBI Class编号 ncbi_taxonomy_id	9606
宿主生物 host_organism	Escherichia coli

Entity 2 Entity 2 non-polymer

Description description	MERCURY (II) ION
Molecular weight formula_weight	200.6 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 3 Entity 3 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	130

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7. Fold Classification (SCOP + CATH) 2 domains

SCOP 2.08 (1 domains)

Domain ID domain_id	d2a1ia1
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.52 — Restriction endonuclease-like
Superfamily Superfamily superfamily	c.52.1 — Restriction endonuclease-like
Family Family family	c.52.1.20 — XPF/Rad1/Mus81 nuclease

CATH v4.4 (1 domains)

Domain ID domain_id	2a1iA01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	10130 —

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8. Citations (1)

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Unit-cell length a length_a	40.070 Å
Unit-cell length b length_b	50.291 Å
Unit-cell length c length_c	72.216 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.00 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	4

Space group space_group	P 21 21 21
Space-group number int_tables_number	19
Crystal system crystal_system	—

Resolution resolution	1.900 Å
Low-resolution limit resolution_low	30.000 Å
R factor r_factor	0.2062
R_work r_work	0.2041
R_free r_free	0.2476

fit	/app/data/saxs_computation/a1/2a1i/2a1i.fit
pddf	/app/data/pr_computation/a1/2a1i/2a1i.pr.out
profile	/app/data/saxs_computation/a1/2a1i/2a1i.dat

Crystal Structure of the Central Domain of Human ERCC1

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

DNA excision repair protein ERCC-1

State in the Current Structure

Other States of the Same Protein in the Database

SAXS scattering curve SAXS Profile

P(r) Distance Distribution P(r) Distribution

2. Structure Basics 2. Structure Basics

3. SAXS Parameters (CRYSOL theoretical calculation) 3. SAXS Parameters (CRYSOL)

4. P(r) Distance Distribution (GNOM inversion) 4. P(r) Analysis (GNOM)

5. Crystallography and Experiment 5. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

Diffraction experiment Diffraction