SAXSdb — 5a21

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

PORTAL PROTEIN

OrganismNot specified

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 8	15 PROTEIN × 2 （Q38584） HEAD COMPLETION PROTEIN GP16 × 2 （O48446） TAIL-TO-HEAD JOINING PROTEIN GP17 × 1 （O48448） MAJOR TAIL PROTEIN 17.1 × 1 （O48449）	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PORTL_BPSPP
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–503； UniProt 1–503 Author chain B； PDBConstruct 1–503； UniProt 1–503

15 PROTEIN

OrganismNot specified

UniProt Q38584

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 8	PORTAL PROTEIN × 2 （P54309） HEAD COMPLETION PROTEIN GP16 × 2 （O48446） TAIL-TO-HEAD JOINING PROTEIN GP17 × 1 （O48448） MAJOR TAIL PROTEIN 17.1 × 1 （O48449）	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	Q38584_BPSPP
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain C； PDBConstruct 1–102； UniProt 1–102 Author chain D； PDBConstruct 1–102； UniProt 1–102

HEAD COMPLETION PROTEIN GP16

OrganismNot specified

UniProt O48446

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 8	PORTAL PROTEIN × 2 （P54309） 15 PROTEIN × 2 （Q38584） TAIL-TO-HEAD JOINING PROTEIN GP17 × 1 （O48448） MAJOR TAIL PROTEIN 17.1 × 1 （O48449）	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	O48446_BPSPP
Isoform	—
PDB entities	3
Chains and sequence ranges	Author chain E； PDBConstruct 1–109； UniProt 1–109 Author chain F； PDBConstruct 1–109； UniProt 1–109

TAIL-TO-HEAD JOINING PROTEIN GP17

OrganismNot specified

UniProt O48448

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 8	PORTAL PROTEIN × 2 （P54309） 15 PROTEIN × 2 （Q38584） HEAD COMPLETION PROTEIN GP16 × 2 （O48446） MAJOR TAIL PROTEIN 17.1 × 1 （O48449）	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	O48448_BPSPP
Isoform	—
PDB entities	4
Chains and sequence ranges	Author chain G； PDBConstruct 1–134； UniProt 1–134

MAJOR TAIL PROTEIN 17.1

OrganismNot specified

UniProt O48449

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 8	PORTAL PROTEIN × 2 （P54309） 15 PROTEIN × 2 （Q38584） HEAD COMPLETION PROTEIN GP16 × 2 （O48446） TAIL-TO-HEAD JOINING PROTEIN GP17 × 1 （O48448）	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	GP171_BPSPP
Isoform	—
PDB entities	5
Chains and sequence ranges	Author chain H； PDBConstruct 1–177； UniProt 1–177

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	5a21
Deposition date deposition_date	2015-05-06
Structure title title	Structure of bacteriophage SPP1 head-to-tail interface without DNA and tape measure protein
Keywords keywords	;VIRAL PROTEIN, VIRAL INFECTION, TAILED BACTERIOPHAGE, SIPHOVIRIDAE, SPP1, VIRAL ASSEMBLY, HEAD-TO-TAIL INTERFACE, DNA GATEKEEPER, ALLOSTERIC MECHANISM, CONCERTED REORGANISATION, DIAPHRAGM GATING ;; VIRAL PROTEIN
Experimental Method method	ELECTRON MICROSCOPY

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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.

5a21__assembly_1__model_1

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

Download this curve (.dat)

5a21__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

5a21__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	65.79 Å
Rg (electron density)	68.27 Å
Total Rg	67.72 Å
Atom count	12789
Residues	1588
Excluded volume	226320 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`5a21__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 (5)

Entity 1 Entity 1 polymer

Description description	PORTAL PROTEIN
Molecular weight formula_weight	57405.4 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B
Atom count atom_count	12789

MADIYPLGKTHTEELNEIIVESAKEIAEPDTTMIQKLIDEHNPEPLLKGVRYYMCENDIEKKRRTYYDAAGQQLVDDTKTNNRTSHAWHKLFVDQKTQYLVGEPVTFTSDNKTLLEYVNELADDDFDDILNETVKNMSNKGIEYWHPFVDEEGEFDYVIFPAEEMIVVYKDNTRRDILFALRYYSYKGIMGEETQKAELYTDTHVYYYEKIDGVYQMDYSYGENNPRPHMTKGGQAIGWGRVPIIPFKNNEEMVSDLKFYKDLIDNYDSITSSTMDSFSDFQQIVYVLKNYDGENPKEFTANLRYHSVIKVSGDGGVDTLRAEIPVDSAAKELERIQDELYKSAQAVDNSPETIGGGATGPALEKLYALLDLKANMAERKIRAGLRLFFWFFAEYLRNTGKGDFNPDKELTMTFTRTRIQNDSEIVQSLVQGVTGGIMSKETAVARNPFVQDPEEELARIEEEMNQYAEMQGNLLDDEGGDDDLEEDDPNAGAAESGGAGQVS

Entity 2 Entity 2 polymer

Description description	15 PROTEIN
Molecular weight formula_weight	11629.4 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

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

MDIQRVKRLLSITNDKHDEYLTEMVPLLVEFAKDECHNPFIDKDGNESIPSGVLIFVAKAAQFYMTNAGLTGRSMDTVSYNFATEIPSTILKKLNPYRKMAR

Entity 3 Entity 3 polymer

Description description	HEAD COMPLETION PROTEIN GP16
Molecular weight formula_weight	12615.1 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

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

MYEEFRDVITFQSYVEQSNGEGGKTYKWVDEFTAAAHVQPISQEEYYKAQQLQTPIGYNIYTPYDDRIDKKMRVIYRGKIVTFIGDPVDLSGLQEITRIKGKEDGAYVG

Entity 4 Entity 4 polymer

Description description	TAIL-TO-HEAD JOINING PROTEIN GP17
Molecular weight formula_weight	15025.0 kDa
Source method src_method	nat
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	G

MTWKLASRALQKATVENLESYQPLMEMVNQVTESPGKDDPYPYVVIGDQSSTPFETKSSFGENITMDFHVWGGTTRAEAQDISSRVLEALTYKPLMFEGFTFVAKKLVLAQVITDTDGVTKHGIIKVRFTINNN

Entity 5 Entity 5 polymer

Description description	MAJOR TAIL PROTEIN 17.1
Molecular weight formula_weight	19172.9 kDa
Source method src_method	nat
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	H

MPETPIMGQDVKYLFQSIDAATGSAPLFPAYQTDGSVSGERELFDEQTKNGRILGPGSVADSGEVTYYGKRGDAGQKAIEDAYQNGKQIKFWRVDTVKNENDKYDAQFGFAYIESREYSDGVEGAVEISISLQVIGELKNGEIDTLPEEIVNVSKGGYDFQQPGQTTGEAPGTVPAP

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Unit-cell length a length_a	1.000 Å
Unit-cell length b length_b	1.000 Å
Unit-cell length c length_c	1.000 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	1

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

Resolution resolution	7.200 Å
Low-resolution limit resolution_low	— Å
R factor r_factor	—
R_work r_work	—
R_free r_free	—

Resolution resolution	7.20 Å
Resolution测定Method resolution_method	ANGULAR RECONSTITUTION
颗粒数 num_particles	18000

Structure of bacteriophage SPP1 head-to-tail interface without DNA and tape measure protein

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

PORTAL PROTEIN

State in the Current Structure

Other States of the Same Protein in the Database

15 PROTEIN

State in the Current Structure

Other States of the Same Protein in the Database

HEAD COMPLETION PROTEIN GP16

State in the Current Structure

Other States of the Same Protein in the Database

TAIL-TO-HEAD JOINING PROTEIN GP17

State in the Current Structure

Other States of the Same Protein in the Database

MAJOR TAIL PROTEIN 17.1

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

5a21__assembly_1__model_1

5a21__assembly_1__model_1 | I(q)

5a21__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

冷冻电镜 EM 3D

5. Entities and Polymers Entities & Polymers (5)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 polymer

Polymer Polymer

Entity 4 Entity 4 polymer

Polymer Polymer

Entity 5 Entity 5 polymer

Polymer Polymer

7. Citations (1)

Structure of bacteriophage SPP1 head-to-tail interface without DNA and tape measure protein

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

PORTAL PROTEIN

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

15 PROTEIN

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

HEAD COMPLETION PROTEIN GP16

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

TAIL-TO-HEAD JOINING PROTEIN GP17

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

MAJOR TAIL PROTEIN 17.1

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

5a21__assembly_1__model_1

5a21__assembly_1__model_1 | I(q)

5a21__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

冷冻电镜 EM 3D

5. Entities and Polymers Entities & Polymers (5)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 polymer

Polymer Polymer

Entity 4 Entity 4 polymer

Polymer Polymer

Entity 5 Entity 5 polymer

Polymer Polymer

7. Citations (1)