2nsi

HUMAN INDUCIBLE NITRIC OXIDE SYNTHASE, ZN-FREE, SEITU COMPLEX

Method: X-RAY DIFFRACTION

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

PROTEIN (NITRIC OXIDE SYNTHASE)

Homo sapiens

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 2	SULFATE ION × 5 PROTOPORPHYRIN IX CONTAINING FE × 2 5,6,7,8-TETRAHYDROBIOPTERIN × 2 ETHYLISOTHIOUREA × 2	Consistent with protein count
2	Protein homooligomer	Homooligomer	Protein 2	SULFATE ION × 4 PROTOPORPHYRIN IX CONTAINING FE × 2 5,6,7,8-TETRAHYDROBIOPTERIN × 2 ETHYLISOTHIOUREA × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	NOS2A_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–431； UniProt 74–504 Author chain B； PDBConstruct 1–431； UniProt 74–504 Author chain C； PDBConstruct 1–431； UniProt 74–504 Author chain D； PDBConstruct 1–431； UniProt 74–504

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	2nsi
Deposition date deposition_date	1999-01-11
Structure title title	HUMAN INDUCIBLE NITRIC OXIDE SYNTHASE, ZN-FREE, SEITU COMPLEX
Keywords keywords	NITRIC OXIDE SYNTHASE, HEME PROTEIN, TETRAHYDROBIOPTERIN, OXIDOREDUCTASE; OXIDOREDUCTASE
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.

2nsi__assembly_1__model_1

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

Download this curve (.dat)

2nsi__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

2nsi__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	30.19 Å
Rg (electron density)	29.35 Å
Total Rg	30.01 Å
Atom count	6995
Residues	840
Excluded volume	123960 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`2nsi__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`2nsi__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 (5)

Entity 1 Entity 1 polymer

Description description	PROTEIN (NITRIC OXIDE SYNTHASE)
Molecular weight formula_weight	49705.5 kDa
EC 编号 ec_number	1.14.13.39
Source method src_method	man
Copy count entity_count	4

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,C,D
Atom count atom_count	13985

LDATPLSSPRHVRIKNWGSGMTFQDTLHHKAKGILTCRSKSCLGSIMTPKSLTRGPRDKPTPPDELLPQAIEFVNQYYGSFKEAKIEEHLARVEAVTKEIETTGTYQLTGDELIFATKQAWRNAPRCIGRIQWSNLQVFDARSCSTAREMFEHICRHVRYSTNNGNIRSAITVFPQRSDGKHDFRVWNAQLIRYAGYQMPDGSIRGDPANVEFTQLCIDLGWKPKYGRFDVVPLVLQANGRDPELFEIPPDLVLEVAMEHPKYEWFRELELKWYALPAVANMLLEVGGLEFPGCPFNGWYMGTEIGVRDFCDVQRYNILEEVGRRMGLETHKLASLWKDQAVVEINIAVLHSFQKQNVTIMDHHSAAESFMKYMQNEYRSRGGCPADWIWLVPPMSGSITPVFHQEMLNYVLSPFYYYQVEAWKTHVWQDE

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 non-polymer

Description description	SULFATE ION
Molecular weight formula_weight	96.1 kDa
Source method src_method	syn
Copy count entity_count	9

Entity 3 Entity 3 non-polymer

Description description	PROTOPORPHYRIN IX CONTAINING FE
Molecular weight formula_weight	616.5 kDa
Source method src_method	syn
Copy count entity_count	4

Entity 4 Entity 4 non-polymer

Description description	5,6,7,8-TETRAHYDROBIOPTERIN
Molecular weight formula_weight	241.2 kDa
Source method src_method	syn
Copy count entity_count	4

Entity 5 Entity 5 non-polymer

Description description	ETHYLISOTHIOUREA
Molecular weight formula_weight	104.2 kDa
Source method src_method	syn
Copy count entity_count	4

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6. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (4 domains)

Domain ID domain_id	d2nsia_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.174 — Nitric oxide (NO) synthase oxygenase domain
Superfamily Superfamily superfamily	d.174.1 — Nitric oxide (NO) synthase oxygenase domain
Family Family family	d.174.1.1 — Nitric oxide (NO) synthase oxygenase domain

Domain ID domain_id	d2nsib_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.174 — Nitric oxide (NO) synthase oxygenase domain
Superfamily Superfamily superfamily	d.174.1 — Nitric oxide (NO) synthase oxygenase domain
Family Family family	d.174.1.1 — Nitric oxide (NO) synthase oxygenase domain

Domain ID domain_id	d2nsic_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.174 — Nitric oxide (NO) synthase oxygenase domain
Superfamily Superfamily superfamily	d.174.1 — Nitric oxide (NO) synthase oxygenase domain
Family Family family	d.174.1.1 — Nitric oxide (NO) synthase oxygenase domain

Domain ID domain_id	d2nsid_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.174 — Nitric oxide (NO) synthase oxygenase domain
Superfamily Superfamily superfamily	d.174.1 — Nitric oxide (NO) synthase oxygenase domain
Family Family family	d.174.1.1 — Nitric oxide (NO) synthase oxygenase domain

CATH v4.4 (12 domains)

Domain ID domain_id	2nsiA01
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	340 — Nitric Oxide Synthase; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — Nitric Oxide Synthase; Chain A, domain 1

Domain ID domain_id	2nsiA02
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	440 — Nitric Oxide Synthase;Heme Domain; Chain A, domain 2
Homologous superfamily homologous superfamily	10 — Nitric Oxide Synthase;Heme Domain;Chain A domain 2

Domain ID domain_id	2nsiA03
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	1230 — Bovine Endothelial Nitric Oxide Synthase Heme Domain; Chain: A,domain 3
Homologous superfamily homologous superfamily	10 — Nitric Oxide Synthase; Chain A, domain 3

Domain ID domain_id	2nsiB01
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	340 — Nitric Oxide Synthase; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — Nitric Oxide Synthase; Chain A, domain 1

Domain ID domain_id	2nsiB02
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	440 — Nitric Oxide Synthase;Heme Domain; Chain A, domain 2
Homologous superfamily homologous superfamily	10 — Nitric Oxide Synthase;Heme Domain;Chain A domain 2

Domain ID domain_id	2nsiB03
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	1230 — Bovine Endothelial Nitric Oxide Synthase Heme Domain; Chain: A,domain 3
Homologous superfamily homologous superfamily	10 — Nitric Oxide Synthase; Chain A, domain 3

Domain ID domain_id	2nsiC01
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	340 — Nitric Oxide Synthase; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — Nitric Oxide Synthase; Chain A, domain 1

Domain ID domain_id	2nsiC02
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	440 — Nitric Oxide Synthase;Heme Domain; Chain A, domain 2
Homologous superfamily homologous superfamily	10 — Nitric Oxide Synthase;Heme Domain;Chain A domain 2

Domain ID domain_id	2nsiC03
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	1230 — Bovine Endothelial Nitric Oxide Synthase Heme Domain; Chain: A,domain 3
Homologous superfamily homologous superfamily	10 — Nitric Oxide Synthase; Chain A, domain 3

Domain ID domain_id	2nsiD01
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	340 — Nitric Oxide Synthase; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — Nitric Oxide Synthase; Chain A, domain 1

Domain ID domain_id	2nsiD02
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	440 — Nitric Oxide Synthase;Heme Domain; Chain A, domain 2
Homologous superfamily homologous superfamily	10 — Nitric Oxide Synthase;Heme Domain;Chain A domain 2

Domain ID domain_id	2nsiD03
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	1230 — Bovine Endothelial Nitric Oxide Synthase Heme Domain; Chain: A,domain 3
Homologous superfamily homologous superfamily	10 — Nitric Oxide Synthase; Chain A, domain 3

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Unit-cell length a length_a	188.370 Å
Unit-cell length b length_b	188.370 Å
Unit-cell length c length_c	230.160 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	32

Space group space_group	P 43 21 2
Space-group number int_tables_number	96
Crystal system crystal_system	—

Resolution resolution	3.000 Å
Low-resolution limit resolution_low	30.000 Å
R factor r_factor	0.2140
R_work r_work	0.2140
R_free r_free	0.2380

HUMAN INDUCIBLE NITRIC OXIDE SYNTHASE, ZN-FREE, SEITU COMPLEX

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

PROTEIN (NITRIC OXIDE SYNTHASE)

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

2nsi__assembly_1__model_1

2nsi__assembly_1__model_1 | I(q)

2nsi__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 (5)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

6. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (4 domains)

CATH v4.4 (12 domains)

7. Citations (4)

HUMAN INDUCIBLE NITRIC OXIDE SYNTHASE, ZN-FREE, SEITU COMPLEX

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

PROTEIN (NITRIC OXIDE SYNTHASE)

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

2nsi__assembly_1__model_1

2nsi__assembly_1__model_1 | I(q)

2nsi__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 (5)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

6. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (4 domains)

CATH v4.4 (12 domains)

7. Citations (4)