3b9j

Structure of Xanthine Oxidase with 2-hydroxy-6-methylpurine

Method: X-RAY DIFFRACTION

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

xanthine oxidase

OrganismNot specified

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 3	FE2/S2 (INORGANIC) CLUSTER × 2 FLAVIN-ADENINE DINUCLEOTIDE × 1 CALCIUM ION × 1 PHOSPHONIC ACIDMONO-(2-AMINO-5,6-DIMERCAPTO-4-OXO-3,7,8A,9,10,10A-HEXAHYDRO-4H-8-OXA-1,3,9,10-TETRAAZA-ANTHRACEN-7-YLMETHYL)ESTER × 1 DIOXOTHIOMOLYBDENUM(VI) ION × 1 6-methyl-3,9-dihydro-2H-purin-2-one × 1 water × 3	Consistent with protein count
2	Protein homooligomer	Homooligomer	Protein 3	FE2/S2 (INORGANIC) CLUSTER × 2 FLAVIN-ADENINE DINUCLEOTIDE × 1 PHOSPHONIC ACIDMONO-(2-AMINO-5,6-DIMERCAPTO-4-OXO-3,7,8A,9,10,10A-HEXAHYDRO-4H-8-OXA-1,3,9,10-TETRAAZA-ANTHRACEN-7-YLMETHYL)ESTER × 1 DIOXOTHIOMOLYBDENUM(VI) ION × 1 6-methyl-3,9-dihydro-2H-purin-2-one × 1 water × 3	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	XDH_BOVIN
Isoform	—
PDB entities	1, 2, 3
Chains and sequence ranges	Author chain A； PDBConstruct 1–219； UniProt 1–219 Author chain I； PDBConstruct 1–219； UniProt 1–219 Author chain B； PDBConstruct 1–350； UniProt 220–569 Author chain J； PDBConstruct 1–350； UniProt 220–569 Author chain C； PDBConstruct 1–763； UniProt 570–1332 Author chain K； PDBConstruct 1–763； UniProt 570–1332

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	3b9j
Deposition date deposition_date	2007-11-05
Structure title title	Structure of Xanthine Oxidase with 2-hydroxy-6-methylpurine
Keywords keywords	oxidoreductase, catalysis, intermediate, substrate orientation, peroxisome; 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.

3b9j__assembly_1__model_1

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

Download this curve (.dat)

3b9j__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

3b9j__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	31.83 Å
Rg (electron density)	31.20 Å
Total Rg	31.76 Å
Atom count	9556
Residues	1225
Excluded volume	170470 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`3b9j__assembly_1__model_1`	trimeric （3）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`3b9j__assembly_2__model_1`	trimeric （3）	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 (10)

Entity 1 Entity 1 polymer

Description description	xanthine oxidase
Molecular weight formula_weight	24036.8 kDa
EC 编号 ec_number	1.17.3.2
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,I
Atom count atom_count	19847

MTADELVFFVNGKKVVEKNADPETTLLAYLRRKLGLRGTKLGCGEGGCGACTVMLSKYDRLQDKIIHFSANACLAPICTLHHVAVTTVEGIGSTKTRLHPVQERIAKSHGSQCGFCTPGIVMSMYTLLRNQPEPTVEEIEDAFQGNLCRCTGYRPILQGFRTFAKNGGCCGGNGNNPNCCMNQKKDHTVTLSPSLFNPEEFMPLDPTQEPIFPPELLRL

Entity 2 Entity 2 polymer

Description description	xanthine oxidase
Molecular weight formula_weight	39005.2 kDa
EC 编号 ec_number	1.17.3.2
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

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

KDVPPKQLRFEGERVTWIQASTLKELLDLKAQHPEAKLVVGNTEIGIEMKFKNQLFPMIICPAWIPELNAVEHGPEGISFGAACALSSVEKTLLEAVAKLPTQKTEVFRGVLEQLRWFAGKQVKSVASLGGNIITASPISDLNPVFMASGTKLTIVSRGTRRTVPMDHTFFPSYRKTLLGPEEILLSIEIPYSREDEFFSAFKQASRREDDIAKVTCGMRVLFQPGSMQVKELALCYGGMADRTISALKTTQKQLSKFWNEKLLQDVCAGLAEELSLSPDAPGGMIEFRRTLTLSFFFKFYLTVLKKLGKDSKDKCGKLDPTYTSATLLFQKDPPANIQLFQEVPNGQSK

Entity 3 Entity 3 polymer

Description description	xanthine oxidase
Molecular weight formula_weight	83964.4 kDa
EC 编号 ec_number	1.17.3.2
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	C,K

EDTVGRPLPHLAAAMQASGEAVYCDDIPRYENELFLRLVTSTRAHAKIKSIDVSEAQKVPGFVCFLSADDIPGSNETGLFNDETVFAKDTVTCVGHIIGAVVADTPEHAERAAHVVKVTYEDLPAIITIEDAIKNNSFYGSELKIEKGDLKKGFSEADNVVSGELYIGGQDHFYLETHCTIAIPKGEEGEMELFVSTQNAMKTQSFVAKMLGVPVNRILVRVKRMGGGFGGKETRSTLVSVAVALAAYKTGHPVRCMLDRNEDMLITGGRHPFLARYKVGFMKTGTIVALEVDHYSNAGNSRDLSHSIMERALFHMDNCYKIPNIRGTGRLCKTNLSSNTAFRGFGGPQALFIAENWMSEVAVTCGLPAEEVRWKNMYKEGDLTHFNQRLEGFSVPRCWDECLKSSQYYARKSEVDKFNKENCWKKRGLCIIPTKFGISFTVPFLNQAGALIHVYTDGSVLVSHGGTEMGQGLHTKMVQVASKALKIPISKIYISETSTNTVPNSSPTAASVSTDIYGQAVYEACQTILKRLEPFKKKNPDGSWEDWVMAAYQDRVSLSTTGFYRTPNLGYSFETNSGNAFHYFTYGVACSEVEIDCLTGDHKNLRTDIVMDVGSSLNPAIDIGQVEGAFVQGLGLFTLEELHYSPEGSLHTRGPSTYKIPAFGSIPTEFRVSLLRDCPNKKAIYASKAVGEPPLFLGASVFFAIKDAIRAARAQHTNNNTKELFRLDSPATPEKIRNACVDKFTTLCVTGAPGNCKPWSLRV

Entity 4 Entity 4 non-polymer

Description description	FE2/S2 (INORGANIC) CLUSTER
Molecular weight formula_weight	175.8 kDa
Source method src_method	syn
Copy count entity_count	4

Entity 5 Entity 5 non-polymer

Description description	FLAVIN-ADENINE DINUCLEOTIDE
Molecular weight formula_weight	785.5 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	1

Entity 7 Entity 7 non-polymer

Description description	PHOSPHONIC ACIDMONO-(2-AMINO-5,6-DIMERCAPTO-4-OXO-3,7,8A,9,10,10A-HEXAHYDRO-4H-8-OXA-1,3,9,10-TETRAAZA-ANTHRACEN-7-YLMETHYL)ESTER
Molecular weight formula_weight	395.4 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 8 Entity 8 non-polymer

Description description	DIOXOTHIOMOLYBDENUM(VI) ION
Molecular weight formula_weight	161.0 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 9 Entity 9 non-polymer

Description description	6-methyl-3,9-dihydro-2H-purin-2-one
Molecular weight formula_weight	150.1 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 10 Entity 10 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	861

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6. Fold Classification (SCOP + CATH) 32 domains

SCOP 2.08 (12 domains)

Domain ID domain_id	d3b9ja1
Class class	a — All alpha proteins
Fold Fold fold	a.56 — CO dehydrogenase ISP C-domain like
Superfamily Superfamily superfamily	a.56.1 — CO dehydrogenase ISP C-domain like
Family Family family	a.56.1.1 — CO dehydrogenase ISP C-domain like

Domain ID domain_id	d3b9ja2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.4 — 2Fe-2S ferredoxin-like
Family Family family	d.15.4.2 — 2Fe-2S ferredoxin domains from multidomain proteins

Domain ID domain_id	d3b9jb1
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.87 — CO dehydrogenase flavoprotein C-domain-like
Superfamily Superfamily superfamily	d.87.2 — CO dehydrogenase flavoprotein C-terminal domain-like
Family Family family	d.87.2.0 — automated matches

Domain ID domain_id	d3b9jb2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.145 — FAD-binding/transporter-associated domain-like
Superfamily Superfamily superfamily	d.145.1 — FAD-binding/transporter-associated domain-like
Family Family family	d.145.1.3 — CO dehydrogenase flavoprotein N-terminal domain-like

Domain ID domain_id	d3b9jc1
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.41 — alpha/beta-Hammerhead
Superfamily Superfamily superfamily	d.41.1 — CO dehydrogenase molybdoprotein N-domain-like
Family Family family	d.41.1.1 — CO dehydrogenase molybdoprotein N-domain-like

Domain ID domain_id	d3b9jc2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.133 — Molybdenum cofactor-binding domain
Superfamily Superfamily superfamily	d.133.1 — Molybdenum cofactor-binding domain
Family Family family	d.133.1.1 — Molybdenum cofactor-binding domain

Domain ID domain_id	d3b9ji1
Class class	a — All alpha proteins
Fold Fold fold	a.56 — CO dehydrogenase ISP C-domain like
Superfamily Superfamily superfamily	a.56.1 — CO dehydrogenase ISP C-domain like
Family Family family	a.56.1.1 — CO dehydrogenase ISP C-domain like

Domain ID domain_id	d3b9ji2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.15 — beta-Grasp (ubiquitin-like)
Superfamily Superfamily superfamily	d.15.4 — 2Fe-2S ferredoxin-like
Family Family family	d.15.4.2 — 2Fe-2S ferredoxin domains from multidomain proteins

Domain ID domain_id	d3b9jj1
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.87 — CO dehydrogenase flavoprotein C-domain-like
Superfamily Superfamily superfamily	d.87.2 — CO dehydrogenase flavoprotein C-terminal domain-like
Family Family family	d.87.2.0 — automated matches

Domain ID domain_id	d3b9jj2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.145 — FAD-binding/transporter-associated domain-like
Superfamily Superfamily superfamily	d.145.1 — FAD-binding/transporter-associated domain-like
Family Family family	d.145.1.3 — CO dehydrogenase flavoprotein N-terminal domain-like

Domain ID domain_id	d3b9jk1
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.41 — alpha/beta-Hammerhead
Superfamily Superfamily superfamily	d.41.1 — CO dehydrogenase molybdoprotein N-domain-like
Family Family family	d.41.1.1 — CO dehydrogenase molybdoprotein N-domain-like

Domain ID domain_id	d3b9jk2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.133 — Molybdenum cofactor-binding domain
Superfamily Superfamily superfamily	d.133.1 — Molybdenum cofactor-binding domain
Family Family family	d.133.1.1 — Molybdenum cofactor-binding domain

CATH v4.4 (20 domains)

Domain ID domain_id	3b9jA01
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	30 — Beta-grasp domain

Domain ID domain_id	3b9jA02
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	150 — DNA polymerase; domain 1
Homologous superfamily homologous superfamily	120 — [2Fe-2S]-binding domain

Domain ID domain_id	3b9jB01
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	43 — Uridine Diphospho-n-acetylenolpyruvylglucosamine Reductase; domain 2
Homologous superfamily homologous superfamily	10 — Uridine Diphospho-n-acetylenolpyruvylglucosamine Reductase, domain 2

Domain ID domain_id	3b9jB02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	465 — Uridine Diphospho-n-acetylenolpyruvylglucosamine Reductase; domain 3
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	3b9jB03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	390 — Enolase-like; domain 1
Homologous superfamily homologous superfamily	50 — CO dehydrogenase flavoprotein, C-terminal domain

Domain ID domain_id	3b9jC01
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	1170 — Aldehyde Oxidoreductase; domain 3
Homologous superfamily homologous superfamily	50 — Aldehyde oxidase/xanthine dehydrogenase, a/b hammerhead

Domain ID domain_id	3b9jC02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	365 — Aldehyde Oxidoreductase; domain 4
Homologous superfamily homologous superfamily	10 — Aldehyde oxidase/xanthine dehydrogenase, molybdopterin binding domain

Domain ID domain_id	3b9jC03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	365 — Aldehyde Oxidoreductase; domain 4
Homologous superfamily homologous superfamily	10 — Aldehyde oxidase/xanthine dehydrogenase, molybdopterin binding domain

Domain ID domain_id	3b9jC04
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	365 — Aldehyde Oxidoreductase; domain 4
Homologous superfamily homologous superfamily	10 — Aldehyde oxidase/xanthine dehydrogenase, molybdopterin binding domain

Domain ID domain_id	3b9jC05
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	365 — Aldehyde Oxidoreductase; domain 4
Homologous superfamily homologous superfamily	10 — Aldehyde oxidase/xanthine dehydrogenase, molybdopterin binding domain

Domain ID domain_id	3b9jI01
Class class	3 — Alpha Beta
Architecture architecture	10 — Roll
Topology topology	20 — Ubiquitin-like (UB roll)
Homologous superfamily homologous superfamily	30 — Beta-grasp domain

Domain ID domain_id	3b9jI02
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	150 — DNA polymerase; domain 1
Homologous superfamily homologous superfamily	120 — [2Fe-2S]-binding domain

Domain ID domain_id	3b9jJ01
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	43 — Uridine Diphospho-n-acetylenolpyruvylglucosamine Reductase; domain 2
Homologous superfamily homologous superfamily	10 — Uridine Diphospho-n-acetylenolpyruvylglucosamine Reductase, domain 2

Domain ID domain_id	3b9jJ02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	465 — Uridine Diphospho-n-acetylenolpyruvylglucosamine Reductase; domain 3
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	3b9jJ03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	390 — Enolase-like; domain 1
Homologous superfamily homologous superfamily	50 — CO dehydrogenase flavoprotein, C-terminal domain

Domain ID domain_id	3b9jK01
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	1170 — Aldehyde Oxidoreductase; domain 3
Homologous superfamily homologous superfamily	50 — Aldehyde oxidase/xanthine dehydrogenase, a/b hammerhead

Domain ID domain_id	3b9jK02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	365 — Aldehyde Oxidoreductase; domain 4
Homologous superfamily homologous superfamily	10 — Aldehyde oxidase/xanthine dehydrogenase, molybdopterin binding domain

Domain ID domain_id	3b9jK03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	365 — Aldehyde Oxidoreductase; domain 4
Homologous superfamily homologous superfamily	10 — Aldehyde oxidase/xanthine dehydrogenase, molybdopterin binding domain

Domain ID domain_id	3b9jK04
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	365 — Aldehyde Oxidoreductase; domain 4
Homologous superfamily homologous superfamily	10 — Aldehyde oxidase/xanthine dehydrogenase, molybdopterin binding domain

Domain ID domain_id	3b9jK05
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	365 — Aldehyde Oxidoreductase; domain 4
Homologous superfamily homologous superfamily	10 — Aldehyde oxidase/xanthine dehydrogenase, molybdopterin binding domain

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Unit-cell length a length_a	133.187 Å
Unit-cell length b length_b	73.794 Å
Unit-cell length c length_c	146.498 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	98.87 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	4

Space group space_group	P 1 21 1
Space-group number int_tables_number	4
Crystal system crystal_system	—

Resolution resolution	2.300 Å
Low-resolution limit resolution_low	144.340 Å
R factor r_factor	0.1970
R_work r_work	0.1940
R_free r_free	0.2630

Structure of Xanthine Oxidase with 2-hydroxy-6-methylpurine

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

xanthine oxidase

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

3b9j__assembly_1__model_1

3b9j__assembly_1__model_1 | I(q)

3b9j__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 (10)

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 non-polymer

Entity 10 Entity 10 water

6. Fold Classification (SCOP + CATH) 32 domains

SCOP 2.08 (12 domains)

CATH v4.4 (20 domains)

7. Citations (1)

Structure of Xanthine Oxidase with 2-hydroxy-6-methylpurine

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

xanthine oxidase

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

3b9j__assembly_1__model_1

3b9j__assembly_1__model_1 | I(q)

3b9j__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 (10)

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 non-polymer

Entity 10 Entity 10 water

6. Fold Classification (SCOP + CATH) 32 domains

SCOP 2.08 (12 domains)

CATH v4.4 (20 domains)

7. Citations (1)