4nos

HUMAN INDUCIBLE NITRIC OXIDE SYNTHASE WITH INHIBITOR

Method: X-RAY DIFFRACTION

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

INDUCIBLE 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	ZINC ION × 1 PROTOPORPHYRIN IX CONTAINING FE × 2 2-AMINO-6-(1,2-DIHYDROXY-PROPYL)-7,8-DIHYDRO-6H-PTERIDIN-4-ONE × 1 ETHYLISOTHIOUREA × 2 5,6,7,8-TETRAHYDROBIOPTERIN × 1 water × 2	Consistent with protein count
2	Protein homooligomer	Homooligomer	Protein 2	ZINC ION × 1 PROTOPORPHYRIN IX CONTAINING FE × 2 ETHYLISOTHIOUREA × 2 5,6,7,8-TETRAHYDROBIOPTERIN × 2 water × 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 1–427； UniProt 82–508 Author chain B； PDBConstruct 1–427； UniProt 82–508 Author chain C； PDBConstruct 1–427； UniProt 82–508 Author chain D； PDBConstruct 1–427； UniProt 82–508

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	4nos
Deposition date deposition_date	1999-02-03
Structure title title	HUMAN INDUCIBLE NITRIC OXIDE SYNTHASE WITH INHIBITOR
Keywords keywords	L-ARGININE MONOOXYGENASE, NITRIC OXIDE, HUMAN, ZNS4, 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.

4nos__assembly_1__model_1

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

Download this curve (.dat)

4nos__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

4nos__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	30.04 Å
Rg (electron density)	29.27 Å
Total Rg	29.88 Å
Atom count	6973
Residues	842
Excluded volume	123720 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`4nos__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`4nos__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	INDUCIBLE NITRIC OXIDE SYNTHASE
Molecular weight formula_weight	49461.4 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	15317

PRHVRIKNWGSGMTFQDTLHHKAKGILTCRSKSCLGSIMTPKSLTRGPRDKPTPPDELLPQAIEFVNQYYGSFKEAKIEEHLARVEAVTKEIETTGTYQLTGDELIFATKQAWRNAPRCIGRIQWSNLQVFDARSCSTAREMFEHICRHVRYSTNNGNIRSAITVFPQRSDGKHDFRVWNAQLIRYAGYQMPDGSIRGDPANVEFTQLCIDLGWKPKYGRFDVVPLVLQANGRDPELFEIPPDLVLEVAMEHPKYEWFRELELKWYALPAVANMLLEVGGLEFPGCPFNGWYMGTEIGVRDFCDVQRYNILEEVGRRMGLETHKLASLWKDQAVVEINIAVIHSFQKQNVTIMDHHSAAESFMKYMQNEYRSRGGCPADWIWLVPPMSGSITPVFHQEMLNYVLSPFYYYQVEAWKTHVWQDEKRRP

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	ZINC ION
Molecular weight formula_weight	65.4 kDa
Source method src_method	syn
Copy count entity_count	2

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	2-AMINO-6-(1,2-DIHYDROXY-PROPYL)-7,8-DIHYDRO-6H-PTERIDIN-4-ONE
Molecular weight formula_weight	239.2 kDa
Source method src_method	syn
Copy count entity_count	1

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

Entity 6 Entity 6 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	3

Entity 7 Entity 7 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	1371

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6. Fold Classification (SCOP + CATH) 16 domains

SCOP 2.08 (4 domains)

Domain ID domain_id	d4nosa_
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	d4nosb_
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	d4nosc_
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	d4nosd_
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	4nosA01
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	4nosA02
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	4nosA03
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	4nosB01
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	4nosB02
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	4nosB03
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	4nosC01
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	4nosC02
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	4nosC03
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	4nosD01
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	4nosD02
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	4nosD03
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	89.759 Å
Unit-cell length b length_b	156.672 Å
Unit-cell length c length_c	190.044 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	16

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

Resolution resolution	2.250 Å
Low-resolution limit resolution_low	8.000 Å
R factor r_factor	—
R_work r_work	0.1990
R_free r_free	0.2890

HUMAN INDUCIBLE NITRIC OXIDE SYNTHASE WITH INHIBITOR

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

INDUCIBLE 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

4nos__assembly_1__model_1

4nos__assembly_1__model_1 | I(q)

4nos__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 non-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) 16 domains

SCOP 2.08 (4 domains)

CATH v4.4 (12 domains)

7. Citations (1)

HUMAN INDUCIBLE NITRIC OXIDE SYNTHASE WITH INHIBITOR

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

INDUCIBLE 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

4nos__assembly_1__model_1

4nos__assembly_1__model_1 | I(q)

4nos__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 non-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) 16 domains

SCOP 2.08 (4 domains)

CATH v4.4 (12 domains)

7. Citations (1)