1k8g

Crystal Structure of the N-terminal domain of Oxytricha nova telomere end binding protein alpha subunit both uncomplexed and complexed with telomeric ssDNA

Method: X-RAY DIFFRACTION

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

Telomere-Binding Protein alpha Subunit

Sterkiella nova

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein–DNA	Monomer	Protein 1 DNA 1	5'-D(TPTPGPGPGP*G)-3' × 1 SULFATE ION × 2 water × 2	Consistent with all polymers
2	Protein–DNA	Monomer	Protein 1 DNA 1	5'-D(TPTPGPGPGP*G)-3' × 1 SULFATE ION × 2 water × 2	Consistent with all polymers
3	Protein monomer	Monomer	Protein 1	SULFATE ION × 2 water × 1	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	TEBA_OXYNO
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain A； PDBConstruct 1–320； UniProt 1–320 Author chain B； PDBConstruct 1–320； UniProt 1–320 Author chain C； PDBConstruct 1–320； UniProt 1–320

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	1k8g
Deposition date deposition_date	2001-10-24
Structure title title	Crystal Structure of the N-terminal domain of Oxytricha nova telomere end binding protein alpha subunit both uncomplexed and complexed with telomeric ssDNA
Keywords keywords	;Protein-DNA Complex, telomeres, sequence specific ssDNA binding protein, OB folds, protein single strand DNA interactions, 3'-DNA end binding protein, telomere end binding protein, DNA BINDING PROTEIN-DNA COMPLEX ;; DNA BINDING PROTEIN/DNA
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.

1k8g__assembly_1__model_1

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

Download this curve (.dat)

1k8g__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1k8g__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	19.82 Å
Rg (electron density)	18.64 Å
Total Rg	19.64 Å
Atom count	2272
Residues	273
Excluded volume	40181 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1k8g__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`1k8g__assembly_2__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`1k8g__assembly_3__model_1`	monomeric （1）	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	5'-D(TPTPGPGPGP*G)-3'
Molecular weight formula_weight	1880.3 kDa
Source method src_method	syn
Copy count entity_count	2

Polymer Polymer

Polymer type type	polydeoxyribonucleotide
Chain IDs strand_id	D,E
Atom count atom_count	7040

TTGGGG

Entity 2 Entity 2 polymer

Description description	Telomere-Binding Protein alpha Subunit
Molecular weight formula_weight	36360.1 kDa
Source method src_method	man
Copy count entity_count	3

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,C

MSTAAKQNRSTSRVSKKKTAAPKEGAAKKSDKGHKYEYVELAKASLTSAQPQHFYAVVIDATFPYKTNQERYICSLKIVDPTLYLKQQKGAGDASDYATLVLYAKRFEDLPIIHRAGDIIRVHRATLRLYNGQRQFNANVFYSSSWALFSTDKRSVTQEINNQDAVSDTTPFSFSSKHATIEKNEISILQNLRKWANQYFSSYSVISSDMYTALNKAQAQKGDFDVVAKILQVHELDEYTNELKLKDASGQVFYTLSLKLKFPHVRTGEVVRIRSATYDETSTQKKVLILSHYSNIITFIQSSKLAKELRAKIQDDHSVE

Source Source

Source organism organism	Sterkiella nova
NCBI taxonomy ID ncbi_taxonomy_id	200597
Host organism host_organism	Escherichia coli

Entity 3 Entity 3 non-polymer

Description description	SULFATE ION
Molecular weight formula_weight	96.1 kDa
Source method src_method	syn
Copy count entity_count	6

Entity 4 Entity 4 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	183

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6. Fold Classification (SCOP + CATH) 12 domains

SCOP 2.08 (6 domains)

Domain ID domain_id	d1k8ga1
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	d1k8ga2
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	d1k8gb1
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	d1k8gb2
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	d1k8gc1
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	d1k8gc2
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 (6 domains)

Domain ID domain_id	1k8gA01
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	1k8gA02
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	1k8gB01
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	1k8gB02
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	1k8gC01
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	1k8gC02
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

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Unit-cell length a length_a	121.182 Å
Unit-cell length b length_b	121.182 Å
Unit-cell length c length_c	137.169 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	P 32 2 1
Space-group number int_tables_number	154
Crystal system crystal_system	—

Resolution resolution	2.600 Å
Low-resolution limit resolution_low	30.000 Å
R factor r_factor	0.2460
R_work r_work	0.2460
R_free r_free	0.2850

Crystal Structure of the N-terminal domain of Oxytricha nova telomere end binding protein alpha subunit both uncomplexed and complexed with telomeric ssDNA

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

Telomere-Binding Protein alpha 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

1k8g__assembly_1__model_1

1k8g__assembly_1__model_1 | I(q)

1k8g__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 (4)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

6. Fold Classification (SCOP + CATH) 12 domains

SCOP 2.08 (6 domains)

CATH v4.4 (6 domains)

7. Citations (1)

Crystal Structure of the N-terminal domain of Oxytricha nova telomere end binding protein alpha subunit both uncomplexed and complexed with telomeric ssDNA

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

Telomere-Binding Protein alpha 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

1k8g__assembly_1__model_1

1k8g__assembly_1__model_1 | I(q)

1k8g__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 (4)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

6. Fold Classification (SCOP + CATH) 12 domains

SCOP 2.08 (6 domains)

CATH v4.4 (6 domains)

7. Citations (1)