1l1o

Structure of the human Replication Protein A (RPA) trimerization core

Method: X-RAY DIFFRACTION

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

Replication protein A 14 kDa subunit

Homo sapiens

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 6	Replication protein A 32 kDa subunit × 2 （P15927） Replication protein A 70 kDa DNA-binding subunit × 2 （P27694） ZINC ION × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	RFA3_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–121； UniProt 1–121 Author chain D； PDBConstruct 1–121； UniProt 1–121

Replication protein A 32 kDa subunit

Homo sapiens

UniProt P15927

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 6	Replication protein A 14 kDa subunit × 2 （P35244） Replication protein A 70 kDa DNA-binding subunit × 2 （P27694） ZINC ION × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	RFA2_HUMAN
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 1–128； UniProt 44–171 Author chain E； PDBConstruct 1–128； UniProt 44–171

Replication protein A 70 kDa DNA-binding subunit

Homo sapiens

UniProt P27694

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 6	Replication protein A 14 kDa subunit × 2 （P35244） Replication protein A 32 kDa subunit × 2 （P15927） ZINC ION × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	RFA1_HUMAN
Isoform	—
PDB entities	3
Chains and sequence ranges	Author chain C； PDBConstruct 1–181； UniProt 436–616 Author chain F； PDBConstruct 1–181； UniProt 436–616

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	1l1o
Deposition date deposition_date	2002-02-19
Structure title title	Structure of the human Replication Protein A (RPA) trimerization core
Keywords keywords	eukaryotic SSB, ssDNA binding protein, OB-fold, DNA BINDING PROTEIN; DNA 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.

1l1o__assembly_1__model_1

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

Download this curve (.dat)

1l1o__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1l1o__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	34.78 Å
Rg (electron density)	34.09 Å
Total Rg	34.59 Å
Atom count	6569
Residues	820
Excluded volume	117590 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1l1o__assembly_1__model_1`	hexameric （6）	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	Replication protein A 14 kDa subunit
Molecular weight formula_weight	13583.7 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,D
Atom count atom_count	6569

MVDMMDLPRSRINAGMLAQFIDKPVCFVGRLEKIHPTGKMFILSDGEGKNGTIELMEPLDEEISGIVEVVGRVTAKATILCTSYVQFKEDSHPFDLGLYNEAVKIIHDFPQFYPLGIVQHD

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 BL21(DE3)

Entity 2 Entity 2 polymer

Description description	Replication protein A 32 kDa subunit
Molecular weight formula_weight	14361.5 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

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

QHIVPCTISQLLSATLVDEVFRIGNVEISQVTIVGIIRHAEKAPTNIVYKIDDMTAAPMDVRQWVDTDDTSSENTVVPPETYVKVAGHLRSFQNKKSLVAFKIMPLEDMNEFTTHILEVINAHMVLSK

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 BL21(DE3)

Entity 3 Entity 3 polymer

Description description	Replication protein A 70 kDa DNA-binding subunit
Molecular weight formula_weight	21145.8 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

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

GGSNTNWKTLYEVKSENLGQGDKPDYFSSVATVVYLRKENCMYQACPTQDCNKKVIDQQNGLYRCEKCDTEFPNFKYRMILSVNIADFQENQWVTCFQESAEAILGQNAAYLGELKDKNEQAFEEVFQNANFRSFIFRVRVKVETYNDESRIKATVMDVKPVDYREYGRRLVMSIRRSALM

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 BL21(DE3)

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	2

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6. Fold Classification (SCOP + CATH) 14 domains

SCOP 2.08 (6 domains)

Domain ID domain_id	d1l1oa_
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.4 — Nucleic acid-binding proteins
Family Family family	b.40.4.3 — Single strand DNA-binding domain, SSB

Domain ID domain_id	d1l1ob_
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.4 — Nucleic acid-binding proteins
Family Family family	b.40.4.3 — Single strand DNA-binding domain, SSB

Domain ID domain_id	d1l1oc_
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.4 — Nucleic acid-binding proteins
Family Family family	b.40.4.3 — Single strand DNA-binding domain, SSB

Domain ID domain_id	d1l1od_
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.4 — Nucleic acid-binding proteins
Family Family family	b.40.4.3 — Single strand DNA-binding domain, SSB

Domain ID domain_id	d1l1oe_
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.4 — Nucleic acid-binding proteins
Family Family family	b.40.4.3 — Single strand DNA-binding domain, SSB

Domain ID domain_id	d1l1of_
Class class	b — All beta proteins
Fold Fold fold	b.40 — OB-fold
Superfamily Superfamily superfamily	b.40.4 — Nucleic acid-binding proteins
Family Family family	b.40.4.3 — Single strand DNA-binding domain, SSB

CATH v4.4 (8 domains)

Domain ID domain_id	1l1oA00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	140 — Nucleic acid-binding proteins

Domain ID domain_id	1l1oB00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	140 — Nucleic acid-binding proteins

Domain ID domain_id	1l1oC01
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	140 — Nucleic acid-binding proteins

Domain ID domain_id	1l1oC02
Class class	2 — Mainly Beta
Architecture architecture	20 — Single Sheet
Topology topology	25 — N-terminal domain of TfIIb
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	1l1oD00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	140 — Nucleic acid-binding proteins

Domain ID domain_id	1l1oE00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	140 — Nucleic acid-binding proteins

Domain ID domain_id	1l1oF01
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	50 — OB fold (Dihydrolipoamide Acetyltransferase, E2P)
Homologous superfamily homologous superfamily	140 — Nucleic acid-binding proteins

Domain ID domain_id	1l1oF02
Class class	2 — Mainly Beta
Architecture architecture	20 — Single Sheet
Topology topology	25 — N-terminal domain of TfIIb
Homologous superfamily homologous superfamily	10 —

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Unit-cell length a length_a	88.527 Å
Unit-cell length b length_b	88.527 Å
Unit-cell length c length_c	341.090 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	12

Space group space_group	P 31 2 1
Space-group number int_tables_number	152
Crystal system crystal_system	—

Resolution resolution	2.800 Å
Low-resolution limit resolution_low	19.920 Å
R factor r_factor	0.2360
R_work r_work	0.2360
R_free r_free	0.2820

Structure of the human Replication Protein A (RPA) trimerization core

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

Replication protein A 14 kDa subunit

State in the Current Structure

Other States of the Same Protein in the Database

Replication protein A 32 kDa subunit

State in the Current Structure

Other States of the Same Protein in the Database

Replication protein A 70 kDa DNA-binding subunit

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

1l1o__assembly_1__model_1

1l1o__assembly_1__model_1 | I(q)

1l1o__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

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 polymer

Polymer Polymer

Source Source

Entity 4 Entity 4 non-polymer

6. Fold Classification (SCOP + CATH) 14 domains

SCOP 2.08 (6 domains)

CATH v4.4 (8 domains)

7. Citations (2)

Structure of the human Replication Protein A (RPA) trimerization core

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

Replication protein A 14 kDa subunit

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Replication protein A 32 kDa subunit

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Replication protein A 70 kDa DNA-binding subunit

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

1l1o__assembly_1__model_1

1l1o__assembly_1__model_1 | I(q)

1l1o__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

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 polymer

Polymer Polymer

Source Source

Entity 4 Entity 4 non-polymer

6. Fold Classification (SCOP + CATH) 14 domains

SCOP 2.08 (6 domains)

CATH v4.4 (8 domains)

7. Citations (2)