1un6

THE CRYSTAL STRUCTURE OF A ZINC FINGER - RNA COMPLEX REVEALS TWO MODES OF MOLECULAR RECOGNITION

Method: X-RAY DIFFRACTION

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

TRANSCRIPTION FACTOR IIIA

XENOPUS LAEVIS

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein–RNA	Monomer	Protein 1 RNA 1	5S RIBOSOMAL RNA × 1 ZINC ION × 3 MAGNESIUM ION × 4 water × 2	Consistent with all polymers
2	Protein–RNA	Homooligomer	Protein 2 RNA 1	5S RIBOSOMAL RNA × 1 ZINC ION × 5 MAGNESIUM ION × 9 water × 3	Consistent with all polymers

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	TF3A_XENLA
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain B； PDBConstruct 2–87； UniProt 127–212 Author chain C； PDBConstruct 2–87； UniProt 127–212 Author chain D； PDBConstruct 2–87； UniProt 127–212

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	1un6
Deposition date deposition_date	2003-09-04
Structure title title	THE CRYSTAL STRUCTURE OF A ZINC FINGER - RNA COMPLEX REVEALS TWO MODES OF MOLECULAR RECOGNITION
Keywords keywords	;RNA-BINDING PROTEIN/RNA, COMPLEX(ZINC FINGER-RNA), TFIIIA, 5S RIBOSOMAL RNA, ZINC FINGER, RNA-PROTEIN COMPLEX, X. LAEVIS, TRANSCRIPTION REGULATION, RNA-BINDING, DNA-BINDING, NUCLEAR PROTEIN, RNA-BINDING PROTEIN-RNA complex ;; RNA-BINDING PROTEIN/RNA
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.

1un6__assembly_1__model_1

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

Download this curve (.dat)

1un6__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1un6__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	23.20 Å
Rg (electron density)	22.50 Å
Total Rg	23.04 Å
Atom count	2032
Residues	148
Excluded volume	31283 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1un6__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`1un6__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 (5)

Entity 1 Entity 1 polymer

Description description	TRANSCRIPTION FACTOR IIIA
Molecular weight formula_weight	10299.8 kDa
Source method src_method	man
Copy count entity_count	3

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B,C,D
Atom count atom_count	4554

MYVCHFENCGKAFKKHNQLKVHQFSHTQQLPYECPHEGCDKRFSLPSRLKRHEKVHAGYPCKKDDSCSFVGKTWTLYLKHVAECHQD

Source Source

Source organism organism	XENOPUS LAEVIS
Common name common_name	AFRICAN CLAWED FROG
NCBI taxonomy ID ncbi_taxonomy_id	8355
Host organism host_organism	ESCHERICHIA COLI

Entity 2 Entity 2 polymer

Description description	5S RIBOSOMAL RNA
Molecular weight formula_weight	19708.8 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polyribonucleotide
Chain IDs strand_id	E,F

GCCGGCCACACCUACGGGGCCUGGUUAGUACCUGGGAAACCUGGGAAUACCAGGUGCCGGC

Entity 3 Entity 3 non-polymer

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

Entity 4 Entity 4 non-polymer

Description description	MAGNESIUM ION
Molecular weight formula_weight	24.3 kDa
Source method src_method	syn
Copy count entity_count	13

Entity 5 Entity 5 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	16

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6. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (8 domains)

Domain ID domain_id	d1un6b1
Class class	g — Small proteins
Fold Fold fold	g.37 — beta-beta-alpha zinc fingers
Superfamily Superfamily superfamily	g.37.1 — beta-beta-alpha zinc fingers
Family Family family	g.37.1.1 — Classic zinc finger, C2H2

Domain ID domain_id	d1un6b2
Class class	g — Small proteins
Fold Fold fold	g.37 — beta-beta-alpha zinc fingers
Superfamily Superfamily superfamily	g.37.1 — beta-beta-alpha zinc fingers
Family Family family	g.37.1.1 — Classic zinc finger, C2H2

Domain ID domain_id	d1un6b3
Class class	g — Small proteins
Fold Fold fold	g.37 — beta-beta-alpha zinc fingers
Superfamily Superfamily superfamily	g.37.1 — beta-beta-alpha zinc fingers
Family Family family	g.37.1.1 — Classic zinc finger, C2H2

Domain ID domain_id	d1un6c1
Class class	g — Small proteins
Fold Fold fold	g.37 — beta-beta-alpha zinc fingers
Superfamily Superfamily superfamily	g.37.1 — beta-beta-alpha zinc fingers
Family Family family	g.37.1.1 — Classic zinc finger, C2H2

Domain ID domain_id	d1un6c2
Class class	g — Small proteins
Fold Fold fold	g.37 — beta-beta-alpha zinc fingers
Superfamily Superfamily superfamily	g.37.1 — beta-beta-alpha zinc fingers
Family Family family	g.37.1.1 — Classic zinc finger, C2H2

Domain ID domain_id	d1un6c3
Class class	g — Small proteins
Fold Fold fold	g.37 — beta-beta-alpha zinc fingers
Superfamily Superfamily superfamily	g.37.1 — beta-beta-alpha zinc fingers
Family Family family	g.37.1.1 — Classic zinc finger, C2H2

Domain ID domain_id	d1un6d1
Class class	g — Small proteins
Fold Fold fold	g.37 — beta-beta-alpha zinc fingers
Superfamily Superfamily superfamily	g.37.1 — beta-beta-alpha zinc fingers
Family Family family	g.37.1.1 — Classic zinc finger, C2H2

Domain ID domain_id	d1un6d2
Class class	g — Small proteins
Fold Fold fold	g.37 — beta-beta-alpha zinc fingers
Superfamily Superfamily superfamily	g.37.1 — beta-beta-alpha zinc fingers
Family Family family	g.37.1.1 — Classic zinc finger, C2H2

CATH v4.4 (8 domains)

Domain ID domain_id	1un6B01
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	160 — Double Stranded RNA Binding Domain
Homologous superfamily homologous superfamily	60 — Classic Zinc Finger

Domain ID domain_id	1un6B02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	160 — Double Stranded RNA Binding Domain
Homologous superfamily homologous superfamily	60 — Classic Zinc Finger

Domain ID domain_id	1un6B03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	160 — Double Stranded RNA Binding Domain
Homologous superfamily homologous superfamily	60 — Classic Zinc Finger

Domain ID domain_id	1un6C01
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	160 — Double Stranded RNA Binding Domain
Homologous superfamily homologous superfamily	60 — Classic Zinc Finger

Domain ID domain_id	1un6C02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	160 — Double Stranded RNA Binding Domain
Homologous superfamily homologous superfamily	60 — Classic Zinc Finger

Domain ID domain_id	1un6C03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	160 — Double Stranded RNA Binding Domain
Homologous superfamily homologous superfamily	60 — Classic Zinc Finger

Domain ID domain_id	1un6D01
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	160 — Double Stranded RNA Binding Domain
Homologous superfamily homologous superfamily	60 — Classic Zinc Finger

Domain ID domain_id	1un6D02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	160 — Double Stranded RNA Binding Domain
Homologous superfamily homologous superfamily	60 — Classic Zinc Finger

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Unit-cell length a length_a	58.598 Å
Unit-cell length b length_b	191.593 Å
Unit-cell length c length_c	79.770 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	101.51 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	12

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	35.190 Å
R factor r_factor	0.2160
R_work r_work	0.2160
R_free r_free	0.2590

THE CRYSTAL STRUCTURE OF A ZINC FINGER - RNA COMPLEX REVEALS TWO MODES OF MOLECULAR RECOGNITION

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

TRANSCRIPTION FACTOR IIIA

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

1un6__assembly_1__model_1

1un6__assembly_1__model_1 | I(q)

1un6__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 (5)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 water

6. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (8 domains)

CATH v4.4 (8 domains)

7. Citations (2)

THE CRYSTAL STRUCTURE OF A ZINC FINGER - RNA COMPLEX REVEALS TWO MODES OF MOLECULAR RECOGNITION

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

TRANSCRIPTION FACTOR IIIA

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

1un6__assembly_1__model_1

1un6__assembly_1__model_1 | I(q)

1un6__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 (5)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 water

6. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (8 domains)

CATH v4.4 (8 domains)

7. Citations (2)