SAXSdb — 1pk3

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

Sex comb on midleg CG9495-PA

Drosophila melanogaster

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein monomer	Monomer	Protein 1	BETA-MERCAPTOETHANOL × 1 water × 1	Consistent with protein count
2	Protein monomer	Monomer	Protein 1	BETA-MERCAPTOETHANOL × 1 water × 1	Consistent with protein count
3	Protein monomer	Monomer	Protein 1	BETA-MERCAPTOETHANOL × 1 water × 1	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	SCM_DROME
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 6–82； UniProt 795–871 Author chain B； PDBConstruct 6–82； UniProt 795–871 Author chain C； PDBConstruct 6–82； UniProt 795–871

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	1pk3
Deposition date deposition_date	2003-06-04
Structure title title	Scm SAM domain
Keywords keywords	SAM domain, polymer, transcriptional repression, transcription repression; transcription repression
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.

1pk3__assembly_3__model_1

Assembly 3 · Model 1 · CRYSOL 4.1.3-1-20251215 (887e7ef)

Download this curve (.dat)

1pk3__assembly_3__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1pk3__assembly_3__model_1 | P(r) · Pending

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

Rg（Guinier）	13.29 Å
Rg (electron density)	11.99 Å
Total Rg	13.42 Å
Atom count	625
Residues	78
Excluded volume	11199 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1pk3__assembly_1__model_1`	monomeric （1）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`1pk3__assembly_2__model_1`	monomeric （1）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`1pk3__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 (3)

Entity 1 Entity 1 polymer

Description description	Sex comb on midleg CG9495-PA
Molecular weight formula_weight	10384.0 kDa
Mutation mutation	L841R
Source method src_method	man
Copy count entity_count	3

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,C
Atom count atom_count	1926

MEKTRANSHLRSQPIDWTIEEVIQYIESNDNSLAVHGDLFRKHEIDGKALLRLNSEMMMKYMGLKLGPALKICNLVNKVNGRDHHHHHH

Source Source

Source organism organism	Drosophila melanogaster
Common name common_name	fruit fly
NCBI taxonomy ID ncbi_taxonomy_id	7227
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 non-polymer

Description description	BETA-MERCAPTOETHANOL
Molecular weight formula_weight	78.1 kDa
Source method src_method	syn
Copy count entity_count	3

Entity 3 Entity 3 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	146

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6. Fold Classification (SCOP + CATH) 8 domains

SCOP 2.08 (5 domains)

Domain ID domain_id	d1pk3a1
Class class	a — All alpha proteins
Fold Fold fold	a.60 — SAM domain-like
Superfamily Superfamily superfamily	a.60.1 — SAM/Pointed domain
Family Family family	a.60.1.2 — SAM (sterile alpha motif) domain

Domain ID domain_id	d1pk3a2
Class class	l — Artifacts
Fold Fold fold	l.1 — Tags
Superfamily Superfamily superfamily	l.1.1 — Tags
Family Family family	l.1.1.1 — Tags

Domain ID domain_id	d1pk3b_
Class class	a — All alpha proteins
Fold Fold fold	a.60 — SAM domain-like
Superfamily Superfamily superfamily	a.60.1 — SAM/Pointed domain
Family Family family	a.60.1.0 — automated matches

Domain ID domain_id	d1pk3c2
Class class	a — All alpha proteins
Fold Fold fold	a.60 — SAM domain-like
Superfamily Superfamily superfamily	a.60.1 — SAM/Pointed domain
Family Family family	a.60.1.0 — automated matches

Domain ID domain_id	d1pk3c3
Class class	l — Artifacts
Fold Fold fold	l.1 — Tags
Superfamily Superfamily superfamily	l.1.1 — Tags
Family Family family	l.1.1.1 — Tags

CATH v4.4 (3 domains)

Domain ID domain_id	1pk3A00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	150 — DNA polymerase; domain 1
Homologous superfamily homologous superfamily	50 — Transcription Factor, Ets-1

Domain ID domain_id	1pk3B00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	150 — DNA polymerase; domain 1
Homologous superfamily homologous superfamily	50 — Transcription Factor, Ets-1

Domain ID domain_id	1pk3C00
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	150 — DNA polymerase; domain 1
Homologous superfamily homologous superfamily	50 — Transcription Factor, Ets-1

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Unit-cell length a length_a	52.150 Å
Unit-cell length b length_b	63.993 Å
Unit-cell length c length_c	103.638 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	12

Space group space_group	P 21 21 21
Space-group number int_tables_number	19
Crystal system crystal_system	—

Resolution resolution	1.850 Å
Low-resolution limit resolution_low	19.840 Å
R factor r_factor	0.2150
R_work r_work	0.2150
R_free r_free	0.2310

Scm SAM domain

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

Sex comb on midleg CG9495-PA

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

1pk3__assembly_3__model_1

1pk3__assembly_3__model_1 | I(q)

1pk3__assembly_3__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 (3)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 water

6. Fold Classification (SCOP + CATH) 8 domains

SCOP 2.08 (5 domains)

CATH v4.4 (3 domains)

7. Citations (1)

Scm SAM domain

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

Sex comb on midleg CG9495-PA

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

1pk3__assembly_3__model_1

1pk3__assembly_3__model_1 | I(q)

1pk3__assembly_3__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 (3)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 water

6. Fold Classification (SCOP + CATH) 8 domains

SCOP 2.08 (5 domains)

CATH v4.4 (3 domains)

7. Citations (1)