1g20

MGATP-BOUND AND NUCLEOTIDE-FREE STRUCTURES OF A NITROGENASE PROTEIN COMPLEX BETWEEN LEU127DEL-FE PROTEIN AND THE MOFE PROTEIN

Method: X-RAY DIFFRACTION

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

NITROGENASE MOLYBDENUM-IRON PROTEIN ALPHA CHAIN

OrganismNot specified

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 8	NITROGENASE MOLYBDENUM-IRON PROTEIN BETA CHAIN × 2 （P07329） NITROGENASE IRON PROTEIN × 4 （P00459） 3-HYDROXY-3-CARBOXY-ADIPIC ACID × 2 FE-MO-S CLUSTER × 2 CALCIUM ION × 2 FE(8)-S(7) CLUSTER × 2 IRON/SULFUR CLUSTER × 2 water × 8	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	NIFD_AZOVI
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–492； UniProt 1–491 Author chain C； PDBConstruct 1–492； UniProt 1–491

NITROGENASE MOLYBDENUM-IRON PROTEIN BETA CHAIN

OrganismNot specified

UniProt P07329

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 8	NITROGENASE MOLYBDENUM-IRON PROTEIN ALPHA CHAIN × 2 （P07328） NITROGENASE IRON PROTEIN × 4 （P00459） 3-HYDROXY-3-CARBOXY-ADIPIC ACID × 2 FE-MO-S CLUSTER × 2 CALCIUM ION × 2 FE(8)-S(7) CLUSTER × 2 IRON/SULFUR CLUSTER × 2 water × 8	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	NIFK_AZOVI
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 1–523； UniProt 1–522 Author chain D； PDBConstruct 1–523； UniProt 1–522

NITROGENASE IRON PROTEIN

OrganismNot specified

UniProt P00459

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 8	NITROGENASE MOLYBDENUM-IRON PROTEIN ALPHA CHAIN × 2 （P07328） NITROGENASE MOLYBDENUM-IRON PROTEIN BETA CHAIN × 2 （P07329） 3-HYDROXY-3-CARBOXY-ADIPIC ACID × 2 FE-MO-S CLUSTER × 2 CALCIUM ION × 2 FE(8)-S(7) CLUSTER × 2 IRON/SULFUR CLUSTER × 2 water × 8	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	NIFH1_AZOVI
Isoform	—
PDB entities	3
Chains and sequence ranges	Author chain E； PDBConstruct 2–289； UniProt 1–289 Author chain F； PDBConstruct 2–289； UniProt 1–289 Author chain G； PDBConstruct 2–289； UniProt 1–289 Author chain H； PDBConstruct 2–289； UniProt 1–289

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	1g20
Deposition date deposition_date	2000-10-16
Structure title title	MGATP-BOUND AND NUCLEOTIDE-FREE STRUCTURES OF A NITROGENASE PROTEIN COMPLEX BETWEEN LEU127DEL-FE PROTEIN AND THE MOFE PROTEIN
Keywords keywords	nitrogen-fixation, Fe protein, MoFe protein, P-cluster and FeMo cofactor, 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.

1g20__assembly_1__model_1

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

Download this curve (.dat)

1g20__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1g20__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	50.42 Å
Rg (electron density)	50.79 Å
Total Rg	50.90 Å
Atom count	23837
Residues	3034
Excluded volume	426300 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1g20__assembly_1__model_1`	octameric （8）	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 (9)

Entity 1 Entity 1 polymer

Description description	NITROGENASE MOLYBDENUM-IRON PROTEIN ALPHA CHAIN
Molecular weight formula_weight	55363.0 kDa
EC 编号 ec_number	1.18.6.1
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,C
Atom count atom_count	24903

MTGMSREEVESLIQEVLEVYPEKARKDRNKHLAVNDPAVTQSKKCIISNKKSQPGLMTIRGCAYAGSKGVVWGPIKDMIHISHGPVGCGQYSRAGRRNYYIGTTGVNAFVTMNFTSDFQEKDIVFGGDKKLAKLIDEVETLFPLNKGISVQSECPIGLIGDDIESVSKVKGAELSKTIVPVRCEGFRGVSQSLGHHIANDAVRDWVLGKRDEDTTFASTPYDVAIIGDYNIGGDAWSSRILLEEMGLRCVAQWSGDGSISEIELTPKVKLNLVHCYRSMNYISRHMEEKYGIPWMEYNFFGPTKTIESLRAIAAKFDESIQKKCEEVIAKYKPEWEAVVAKYRPRLEGKRVMLYIGGLRPRHVIGAYEDLGMEVVGTGYEFAHNDDYDRTMKEMGDSTLLYDDVTGYEFEEFVKRIKPDLIGSGIKEKFIFQKMGIPFREMHSWDYSGPYHGFDGFAIFARDMDMTLNNPCWKKLQAPWEASEGAEKVAASA

Entity 2 Entity 2 polymer

Description description	NITROGENASE MOLYBDENUM-IRON PROTEIN BETA CHAIN
Molecular weight formula_weight	59535.9 kDa
EC 编号 ec_number	1.18.6.1
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

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

MSQQVDKIKASYPLFLDQDYKDMLAKKRDGFEEKYPQDKIDEVFQWTTTKEYQELNFQREALTVNPAKACQPLGAVLCALGFEKTMPYVHGSQGCVAYFRSYFNRHFREPVSCVSDSMTEDAAVFGGQQNMKDGLQNCKATYKPDMIAVSTTCMAEVIGDDLNAFINNSKKEGFIPDEFPVPFAHTPSFVGSHVTGWDNMFEGIARYFTLKSMDDKVVGSNKKINIVPGFETYLGNFRVIKRMLSEMGVGYSLLSDPEEVLDTPADGQFRMYAGGTTQEEMKDAPNALNTVLLQPWHLEKTKKFVEGTWKHEVPKLNIPMGLDWTDEFLMKVSEISGQPIPASLTKERGRLVDMMTDSHTWLHGKRFALWGDPDFVMGLVKFLLELGCEPVHILCHNGNKRWKKAVDAILAASPYGKNATVYIGKDLWHLRSLVFTDKPDFMIGNSYGKFIQRDTLHKGKEFEVPLIRIGFPIFDRHHLHRSTTLGYEGAMQILTTLVNSILERLDEETRGMQATDYNHDLVR

Entity 3 Entity 3 polymer

Description description	NITROGENASE IRON PROTEIN
Molecular weight formula_weight	31435.1 kDa
EC 编号 ec_number	1.18.6.1
Source method src_method	nat
Copy count entity_count	4

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	E,F,G,H

MAMRQCAIYGKGGIGKSTTTQNLVAALAEMGKKVMIVGCDPKADSTRLILHSKAQNTIMEMAAEAGTVEDLELEDVLKAGYGGVKCVESGGPEPGVGCAGRGVITAINFLEEEGAYEDDLDFVFYDVGDVVCGGFAMPIRENKAQEIYIVCSGEMMAMYAANNISKGIVKYANSGSVRLGGLICNSRNTDREDELIIALANKLGTQMIHFVPRDNVVQRAEIRRMTVIEYDPKAKQADEYRALARKVVDNKLLVIPNPITMDELEELLMEFGIMEVEDESIVGKTAEEV

Entity 4 Entity 4 non-polymer

Description description	3-HYDROXY-3-CARBOXY-ADIPIC ACID
Molecular weight formula_weight	206.2 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 5 Entity 5 non-polymer

Description description	FE-MO-S CLUSTER
Molecular weight formula_weight	775.4 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 6 Entity 6 non-polymer

Description description	CALCIUM ION
Molecular weight formula_weight	40.1 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 7 Entity 7 non-polymer

Description description	FE(8)-S(7) CLUSTER
Molecular weight formula_weight	671.2 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 8 Entity 8 non-polymer

Description description	IRON/SULFUR CLUSTER
Molecular weight formula_weight	351.6 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 9 Entity 9 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	1066

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6. Fold Classification (SCOP + CATH) 26 domains

SCOP 2.08 (8 domains)

Domain ID domain_id	d1g20a_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.92 — Chelatase-like
Superfamily Superfamily superfamily	c.92.2 — 'Helical backbone' metal receptor
Family Family family	c.92.2.3 — Nitrogenase iron-molybdenum protein

Domain ID domain_id	d1g20b_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.92 — Chelatase-like
Superfamily Superfamily superfamily	c.92.2 — 'Helical backbone' metal receptor
Family Family family	c.92.2.3 — Nitrogenase iron-molybdenum protein

Domain ID domain_id	d1g20c_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.92 — Chelatase-like
Superfamily Superfamily superfamily	c.92.2 — 'Helical backbone' metal receptor
Family Family family	c.92.2.3 — Nitrogenase iron-molybdenum protein

Domain ID domain_id	d1g20d_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.92 — Chelatase-like
Superfamily Superfamily superfamily	c.92.2 — 'Helical backbone' metal receptor
Family Family family	c.92.2.3 — Nitrogenase iron-molybdenum protein

Domain ID domain_id	d1g20e_
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.37.1.10 — Nitrogenase iron protein-like

Domain ID domain_id	d1g20f_
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.37.1.10 — Nitrogenase iron protein-like

Domain ID domain_id	d1g20g_
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.37.1.10 — Nitrogenase iron protein-like

Domain ID domain_id	d1g20h_
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.37.1.10 — Nitrogenase iron protein-like

CATH v4.4 (18 domains)

Domain ID domain_id	1g20A01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	1980 — Nitrogenase molybdenum iron protein domain

Domain ID domain_id	1g20A02
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	1980 — Nitrogenase molybdenum iron protein domain

Domain ID domain_id	1g20A03
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	1980 — Nitrogenase molybdenum iron protein domain

Domain ID domain_id	1g20B01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	1980 — Nitrogenase molybdenum iron protein domain

Domain ID domain_id	1g20B02
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	1980 — Nitrogenase molybdenum iron protein domain

Domain ID domain_id	1g20B03
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	1980 — Nitrogenase molybdenum iron protein domain

Domain ID domain_id	1g20B04
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	89 — Nitrogenase Molybdenum-iron Protein, subunit B; domain 4
Homologous superfamily homologous superfamily	10 — Nitrogenase Molybdenum-iron Protein, subunit B, domain 4

Domain ID domain_id	1g20C01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	1980 — Nitrogenase molybdenum iron protein domain

Domain ID domain_id	1g20C02
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	1980 — Nitrogenase molybdenum iron protein domain

Domain ID domain_id	1g20C03
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	1980 — Nitrogenase molybdenum iron protein domain

Domain ID domain_id	1g20D01
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	1980 — Nitrogenase molybdenum iron protein domain

Domain ID domain_id	1g20D02
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	1980 — Nitrogenase molybdenum iron protein domain

Domain ID domain_id	1g20D03
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	1980 — Nitrogenase molybdenum iron protein domain

Domain ID domain_id	1g20D04
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	89 — Nitrogenase Molybdenum-iron Protein, subunit B; domain 4
Homologous superfamily homologous superfamily	10 — Nitrogenase Molybdenum-iron Protein, subunit B, domain 4

Domain ID domain_id	1g20E00
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	1g20F00
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	1g20G00
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	1g20H00
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

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Unit-cell length a length_a	264.240 Å
Unit-cell length b length_b	111.460 Å
Unit-cell length c length_c	121.590 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	97.40 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	16

Space group space_group	C 1 2 1
Space-group number int_tables_number	5
Crystal system crystal_system	—

Resolution resolution	2.200 Å
Low-resolution limit resolution_low	20.000 Å
R factor r_factor	0.2205
R_work r_work	0.2185
R_free r_free	0.2554

MGATP-BOUND AND NUCLEOTIDE-FREE STRUCTURES OF A NITROGENASE PROTEIN COMPLEX BETWEEN LEU127DEL-FE PROTEIN AND THE MOFE PROTEIN

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

NITROGENASE MOLYBDENUM-IRON PROTEIN ALPHA CHAIN

State in the Current Structure

Other States of the Same Protein in the Database

NITROGENASE MOLYBDENUM-IRON PROTEIN BETA CHAIN

State in the Current Structure

Other States of the Same Protein in the Database

NITROGENASE IRON PROTEIN

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

1g20__assembly_1__model_1

1g20__assembly_1__model_1 | I(q)

1g20__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 (9)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 polymer

Polymer Polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 non-polymer

Entity 8 Entity 8 non-polymer

Entity 9 Entity 9 water

6. Fold Classification (SCOP + CATH) 26 domains

SCOP 2.08 (8 domains)

CATH v4.4 (18 domains)

7. Citations (1)

MGATP-BOUND AND NUCLEOTIDE-FREE STRUCTURES OF A NITROGENASE PROTEIN COMPLEX BETWEEN LEU127DEL-FE PROTEIN AND THE MOFE PROTEIN

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

NITROGENASE MOLYBDENUM-IRON PROTEIN ALPHA CHAIN

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

NITROGENASE MOLYBDENUM-IRON PROTEIN BETA CHAIN

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

NITROGENASE IRON PROTEIN

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

1g20__assembly_1__model_1

1g20__assembly_1__model_1 | I(q)

1g20__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 (9)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 polymer

Polymer Polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 non-polymer

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 non-polymer

Entity 8 Entity 8 non-polymer

Entity 9 Entity 9 water

6. Fold Classification (SCOP + CATH) 26 domains

SCOP 2.08 (8 domains)

CATH v4.4 (18 domains)

7. Citations (1)