SAXSdb — 9i4r

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

Streptavidin

Streptomyces avidinii

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 8	Oic-P-streptagII × 4 GLYCEROL × 1 water × 6	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	SAV_STRAV
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain B； PDBConstruct 14–158； UniProt 39–183 Author chain C； PDBConstruct 14–158； UniProt 39–183 Author chain D； PDBConstruct 14–158； UniProt 39–183 Author chain E； PDBConstruct 14–158； UniProt 39–183

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	9i4r
Deposition date deposition_date	2025-01-26
Last revision last_revision	2025-10-29
Structure title title	N-terminal Oic streptag II in Sav E44V-S45T-V47R-D67A-K121R variant
Keywords keywords	Artificial enzyme, peptide binding protein, streptag, streptavidin, PROTEIN BINDING; PROTEIN BINDING
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.

9i4r__assembly_1__model_1

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

Download this curve (.dat)

9i4r__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

9i4r__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	22.98 Å
Rg (electron density)	21.91 Å
Total Rg	22.87 Å
Atom count	7418
Residues	508
Excluded volume	66961 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`9i4r__assembly_1__model_1`	octameric （8）	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	Streptavidin
Molecular weight formula_weight	16462.9 kDa
Source method src_method	man
Copy count entity_count	4

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B,C,D,E
Atom count atom_count	7558

ASMTGGQQMGRDQAGITGTWYNQLGSTFIVTAGADGALTGTYVTARGNAESRYVLTGRYDSAPATAGSGTALGWTVAWKNNYRNAHSATTWSGQYVGGAEARINTQWLLTSGTTEANAWRSTLVGHDTFTKVQPSAASIDAAKKAGVNNGNPLDAVQQ

Source Source

Source organism organism	Streptomyces avidinii
NCBI taxonomy ID ncbi_taxonomy_id	1895
Host organism host_organism	Escherichia coli BL21(DE3)

Entity 2 Entity 2 polymer

Description description	Oic-P-streptagII
Molecular weight formula_weight	1308.5 kDa
Source method src_method	syn
Copy count entity_count	4

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	F,G,H,I

XPWSHPQFEK

Entity 3 Entity 3 non-polymer

Description description	GLYCEROL
Molecular weight formula_weight	92.1 kDa
Source method src_method	nat
Copy count entity_count	1

Entity 4 Entity 4 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	140

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Unit-cell length a length_a	47.550 Å
Unit-cell length b length_b	105.892 Å
Unit-cell length c length_c	51.246 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	106.45 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	8

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

Resolution resolution	1.840 Å
Low-resolution limit resolution_low	19.480 Å
R factor r_factor	0.1778
R_work r_work	0.1759
R_free r_free	0.2129

N-terminal Oic streptag II in Sav E44V-S45T-V47R-D67A-K121R variant

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

Streptavidin

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

9i4r__assembly_1__model_1

9i4r__assembly_1__model_1 | I(q)

9i4r__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

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

7. Citations (1)

N-terminal Oic streptag II in Sav E44V-S45T-V47R-D67A-K121R variant

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

Streptavidin

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

9i4r__assembly_1__model_1

9i4r__assembly_1__model_1 | I(q)

9i4r__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

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

7. Citations (1)