SAXSdb — 1gka

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

CRUSTACYANIN A2 SUBUNIT

OrganismNot specified

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	CRUSTACYANIN A1 SUBUNIT × 1 ASTAXANTHIN × 2 DODECANE × 1 2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL × 1 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID × 1 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	CRA2_HOMGA
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 1–174； UniProt 1–174

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	1gka
Deposition date deposition_date	2001-08-10
Structure title title	The molecular basis of the coloration mechanism in lobster shell. beta-crustacyanin at 3.2 A resolution
Keywords keywords	LIPOCALIN, CRUSTACYANIN, LOBSTER, ASTAXANTHIN, BATHOCHROMIC, COLORATION; LIPOCALIN
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.

1gka__assembly_1__model_1

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

Download this curve (.dat)

1gka__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1gka__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	25.31 Å
Rg (electron density)	24.01 Å
Total Rg	24.92 Å
Atom count	2966
Residues	354
Excluded volume	52946 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1gka__assembly_1__model_1`	dimeric （2）	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 (7)

Entity 1 Entity 1 polymer

Description description	CRUSTACYANIN A1 SUBUNIT
Molecular weight formula_weight	20558.0 kDa
Source method src_method	nat
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A
Atom count atom_count	2996

KIPNFVVPGKCASVDRNKLWAEQTPNRNSYAGVWYQFALTNNPYQLIEKCVRNEYSFDGKQFVIKSTGIAYDGNLLKRNGKLYPNPFGEPHLSIDYENSFAAPLVILETDYSNYACLYSCIDYNFGYHSDFSFIFSRSANLADQYVKKCEAAFKNINVDTTRFVKTVQGSSCPYDTQKTV

Entity 2 Entity 2 polymer

Description description	CRUSTACYANIN A2 SUBUNIT
Molecular weight formula_weight	19688.8 kDa
Source method src_method	nat
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B

DGIPSFVTAGKCASVANQDNFDLRRYAGRWYQTHIIENAYQPVTRCIHSNYEYSTNDYGFKVTTAGFNPNDEYLKIDFKVYPTKEFPAAHMLIDAPSVFAAPYEVIETDYETYSCVYSCITTDNYKSEFAFVFSRTPQTSGPAVEKTAAVFNKNGVEFSKFVPVSHTAECVYRA

Entity 3 Entity 3 non-polymer

Description description	ASTAXANTHIN
Molecular weight formula_weight	596.8 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 4 Entity 4 non-polymer

Description description	DODECANE
Molecular weight formula_weight	170.3 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 5 Entity 5 non-polymer

Description description	2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL
Molecular weight formula_weight	122.1 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 6 Entity 6 non-polymer

Description description	4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID
Molecular weight formula_weight	238.3 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 7 Entity 7 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	30

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6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

Domain ID domain_id	d1gkaa_
Class class	b — All beta proteins
Fold Fold fold	b.60 — Lipocalins
Superfamily Superfamily superfamily	b.60.1 — Lipocalins
Family Family family	b.60.1.1 — Retinol binding protein-like

Domain ID domain_id	d1gkab_
Class class	b — All beta proteins
Fold Fold fold	b.60 — Lipocalins
Superfamily Superfamily superfamily	b.60.1 — Lipocalins
Family Family family	b.60.1.1 — Retinol binding protein-like

CATH v4.4 (2 domains)

Domain ID domain_id	1gkaA00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	128 — Lipocalin
Homologous superfamily homologous superfamily	20 — Calycin beta-barrel core domain

Domain ID domain_id	1gkaB00
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	128 — Lipocalin
Homologous superfamily homologous superfamily	20 — Calycin beta-barrel core domain

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Unit-cell length a length_a	155.466 Å
Unit-cell length b length_b	155.466 Å
Unit-cell length c length_c	168.504 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	12

Space group space_group	P 63 2 2
Space-group number int_tables_number	182
Crystal system crystal_system	—

Resolution resolution	3.230 Å
Low-resolution limit resolution_low	100.000 Å
R factor r_factor	0.2133
R_work r_work	0.2133
R_free r_free	0.2515

The molecular basis of the coloration mechanism in lobster shell. beta-crustacyanin at 3.2 A resolution

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

CRUSTACYANIN A2 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

1gka__assembly_1__model_1

1gka__assembly_1__model_1 | I(q)

1gka__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 (7)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 water

6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)

The molecular basis of the coloration mechanism in lobster shell. beta-crustacyanin at 3.2 A resolution

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

CRUSTACYANIN A2 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

1gka__assembly_1__model_1

1gka__assembly_1__model_1 | I(q)

1gka__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 (7)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 water

6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (1)