2ik8

Crystal structure of the heterodimeric complex of human RGS16 and activated Gi alpha 1

Method: X-RAY DIFFRACTION

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

Guanine nucleotide-binding protein G(i), alpha-1 subunit

Homo sapiens

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	Regulator of G-protein signaling 16 × 1 （O15492） TETRAFLUOROALUMINATE ION × 1 MAGNESIUM ION × 1 SULFATE ION × 5 GUANOSINE-5'-DIPHOSPHATE × 1 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 2	Regulator of G-protein signaling 16 × 1 （O15492） TETRAFLUOROALUMINATE ION × 1 MAGNESIUM ION × 1 SULFATE ION × 3 GUANOSINE-5'-DIPHOSPHATE × 1 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	GNAI1_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–324； UniProt 30–353 Author chain C； PDBConstruct 1–324； UniProt 30–353

Regulator of G-protein signaling 16

Homo sapiens

UniProt O15492

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	Guanine nucleotide-binding protein G(i), alpha-1 subunit × 1 （P63096） TETRAFLUOROALUMINATE ION × 1 MAGNESIUM ION × 1 SULFATE ION × 5 GUANOSINE-5'-DIPHOSPHATE × 1 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 2	Guanine nucleotide-binding protein G(i), alpha-1 subunit × 1 （P63096） TETRAFLUOROALUMINATE ION × 1 MAGNESIUM ION × 1 SULFATE ION × 3 GUANOSINE-5'-DIPHOSPHATE × 1 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	RGS16_HUMAN
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 3–140； UniProt 53–190 Author chain D； PDBConstruct 3–140； UniProt 53–190

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	2ik8
Deposition date deposition_date	2006-10-02
Structure title title	Crystal structure of the heterodimeric complex of human RGS16 and activated Gi alpha 1
Keywords keywords	;G protein signalling, RGS, heterotrimeric G protein, signalling complex, Structural Genomics, Structural Genomics Consortium, SGC, SIGNALING PROTEIN ;; SIGNALING PROTEIN
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.

2ik8__assembly_1__model_1

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

Download this curve (.dat)

2ik8__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

2ik8__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	23.26 Å
Rg (electron density)	22.16 Å
Total Rg	23.03 Å
Atom count	3365
Residues	430
Excluded volume	59582 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`2ik8__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`2ik8__assembly_2__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	Guanine nucleotide-binding protein G(i), alpha-1 subunit
Molecular weight formula_weight	37102.3 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,C
Atom count atom_count	6814

AREVKLLLLGAGESGKSTIVKQMKIIHEAGYSEEECKQYKAVVYSNTIQSIIAIIRAMGRLKIDFGDSARADDARQLFVLAGAAEEGFMTAELAGVIKRLWKDSGVQACFNRSREYQLNDSAAYYLNDLDRIAQPNYIPTQQDVLRTRVKTTGIVETHFTFKDLHFKMFDVGGQRSERKKWIHCFEGVTAIIFCVALSDYDLVLAEDEEMNRMHESMKLFDSICNNKWFTDTSIILFLNKKDLFEEKIKKSPLTICYPEYAGSNTYEEAAAYIQCQFEDLNKRKDTKEIYTHFTCATDTKNVQFVFDAVTDVIIKNNLKDCGLF

Source Source

Source organism organism	Homo sapiens
Common name common_name	human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 polymer

Description description	Regulator of G-protein signaling 16
Molecular weight formula_weight	15917.9 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

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

SMRNFSEDVLGWRESFDLLLSSKNGVAAFHAFLKTEFSEENLEFWLACEEFKKIRSATKLASRAHQIFEEFICSEAPKEVNIDHETRELTRMNLQTATATCFDAAQGKTRTLMEKDSYPRFLKSPAYRDLAAQASAASAT

Source Source

Source organism organism	Homo sapiens
Common name common_name	human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Escherichia coli

Entity 3 Entity 3 non-polymer

Description description	TETRAFLUOROALUMINATE ION
Molecular weight formula_weight	103.0 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 4 Entity 4 non-polymer

Description description	MAGNESIUM ION
Molecular weight formula_weight	24.3 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 5 Entity 5 non-polymer

Description description	SULFATE ION
Molecular weight formula_weight	96.1 kDa
Source method src_method	syn
Copy count entity_count	8

Entity 6 Entity 6 non-polymer

Description description	GUANOSINE-5'-DIPHOSPHATE
Molecular weight formula_weight	443.2 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 7 Entity 7 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	36

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6. Fold Classification (SCOP + CATH) 14 domains

SCOP 2.08 (6 domains)

Domain ID domain_id	d2ik8a1
Class class	a — All alpha proteins
Fold Fold fold	a.66 — Transducin (alpha subunit), insertion domain
Superfamily Superfamily superfamily	a.66.1 — Transducin (alpha subunit), insertion domain
Family Family family	a.66.1.1 — Transducin (alpha subunit), insertion domain

Domain ID domain_id	d2ik8a2
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.37 — P-loop containing nucleoside triphosphate hydrolases
Superfamily Superfamily superfamily	c.37.1 — P-loop containing nucleoside triphosphate hydrolases
Family Family family	c.37.1.8 — G proteins

Domain ID domain_id	d2ik8b1
Class class	a — All alpha proteins
Fold Fold fold	a.91 — Regulator of G-protein signaling, RGS
Superfamily Superfamily superfamily	a.91.1 — Regulator of G-protein signaling, RGS
Family Family family	a.91.1.1 — Regulator of G-protein signaling, RGS

Domain ID domain_id	d2ik8c1
Class class	a — All alpha proteins
Fold Fold fold	a.66 — Transducin (alpha subunit), insertion domain
Superfamily Superfamily superfamily	a.66.1 — Transducin (alpha subunit), insertion domain
Family Family family	a.66.1.1 — Transducin (alpha subunit), insertion domain

Domain ID domain_id	d2ik8c2
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.37 — P-loop containing nucleoside triphosphate hydrolases
Superfamily Superfamily superfamily	c.37.1 — P-loop containing nucleoside triphosphate hydrolases
Family Family family	c.37.1.8 — G proteins

Domain ID domain_id	d2ik8d_
Class class	a — All alpha proteins
Fold Fold fold	a.91 — Regulator of G-protein signaling, RGS
Superfamily Superfamily superfamily	a.91.1 — Regulator of G-protein signaling, RGS
Family Family family	a.91.1.1 — Regulator of G-protein signaling, RGS

CATH v4.4 (8 domains)

Domain ID domain_id	2ik8A01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	300 — P-loop containing nucleotide triphosphate hydrolases

Domain ID domain_id	2ik8A02
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	400 — GI Alpha 1, domain 2-like
Homologous superfamily homologous superfamily	10 — GI Alpha 1, domain 2-like

Domain ID domain_id	2ik8B01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	196 — Regulator of G-protein Signalling 4; domain 1
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	2ik8B02
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	167 — Regulator of G-protein Signalling 4; domain 2
Homologous superfamily homologous superfamily	10 — Regulator of G-protein Signalling 4, domain 2

Domain ID domain_id	2ik8C01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	300 — P-loop containing nucleotide triphosphate hydrolases

Domain ID domain_id	2ik8C02
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	400 — GI Alpha 1, domain 2-like
Homologous superfamily homologous superfamily	10 — GI Alpha 1, domain 2-like

Domain ID domain_id	2ik8D01
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	196 — Regulator of G-protein Signalling 4; domain 1
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	2ik8D02
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	167 — Regulator of G-protein Signalling 4; domain 2
Homologous superfamily homologous superfamily	10 — Regulator of G-protein Signalling 4, domain 2

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Unit-cell length a length_a	82.656 Å
Unit-cell length b length_b	104.312 Å
Unit-cell length c length_c	124.048 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	8

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

Resolution resolution	2.710 Å
Low-resolution limit resolution_low	49.600 Å
R factor r_factor	0.2354
R_work r_work	0.2325
R_free r_free	0.2911

Crystal structure of the heterodimeric complex of human RGS16 and activated Gi alpha 1

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

Guanine nucleotide-binding protein G(i), alpha-1 subunit

State in the Current Structure

Other States of the Same Protein in the Database

Regulator of G-protein signaling 16

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

2ik8__assembly_1__model_1

2ik8__assembly_1__model_1 | I(q)

2ik8__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

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

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) 14 domains

SCOP 2.08 (6 domains)

CATH v4.4 (8 domains)

7. Citations (1)

Crystal structure of the heterodimeric complex of human RGS16 and activated Gi alpha 1

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

Guanine nucleotide-binding protein G(i), alpha-1 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

Regulator of G-protein signaling 16

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

2ik8__assembly_1__model_1

2ik8__assembly_1__model_1 | I(q)

2ik8__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

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

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) 14 domains

SCOP 2.08 (6 domains)

CATH v4.4 (8 domains)

7. Citations (1)