1iru

Crystal Structure of the mammalian 20S proteasome at 2.75 A resolution

Method: X-RAY DIFFRACTION

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

20S proteasome

OrganismNot specified

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 28	20S proteasome × 2 20S proteasome × 2 20S proteasome × 2 20S proteasome × 2 20S proteasome × 2 20S proteasome × 2 20S proteasome × 2 20S proteasome × 2 20S proteasome × 2 20S proteasome × 2 20S proteasome × 2 20S proteasome × 2 20S proteasome × 2 MAGNESIUM ION × 30 water × 26	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	PSB3_BOVIN
Isoform	—
PDB entities	10
Chains and sequence ranges	Author chain J； PDBConstruct 14–205； UniProt 1–192 Author chain X； PDBConstruct 14–205； UniProt 1–192

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	1iru
Deposition date deposition_date	2001-10-24
Structure title title	Crystal Structure of the mammalian 20S proteasome at 2.75 A resolution
Keywords keywords	20S proteasome, cell cycle, Immune response, proteolysis, ubiquitin, HYDROLASE; HYDROLASE
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.

1iru__assembly_1__model_1

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

Download this curve (.dat)

1iru__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1iru__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	60.09 Å
Rg (electron density)	59.51 Å
Total Rg	59.58 Å
Atom count	47592
Residues	6286
Excluded volume	844520 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1iru__assembly_1__model_1`	28-meric （28）	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 (16)

Entity 1 Entity 1 polymer

Description description	20S proteasome
Molecular weight formula_weight	27432.5 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,O
Atom count atom_count	47757

MSRGSSAGFDRHITIFSPEGRLYQVEYAFKAINQGGLTSVAVRGKDCAVIVTQKKVPDKLLDSSTVTHLFKITENIGCVMTGMTADSRSQVQRARYEAANWKYKYGYEIPVDMLCKRIADISQVYTQNAEMRPLGCCMILIGIDEEQGPQVYKCDPAGYYCGFKATAAGVKQTESTSFLEKKVKKKFDWTFEQTVETAITCLSTVLSIDFKPSEIEVGVVTVENPKFRILTEAEIDAHLVALAERD

Entity 2 Entity 2 polymer

Description description	20S proteasome
Molecular weight formula_weight	25796.3 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

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

AERGYSFSLTTFSPSGKLVQIEYALAAVAGGAPSVGIKAANGVVLATEKKQKSILYDERSVHKVEPITKHIGLVYSGMGPDYRVLVHRARKLAQQYYLVYQEPIPTAQLVQRVASVMQEYTQSGGVRPFGVSLLICGWNEGRPYLFQSDPSGAYFAWKATAMGKNYVNGKTFLEKRYNEDLELEDAIHTAILTLKESFEGQMTEDNIEVGICNEAGFRRLTPTEVKDYLAAIA

Entity 3 Entity 3 polymer

Description description	20S proteasome
Molecular weight formula_weight	29525.8 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

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

MSRRYDSRTTIFSPEGRLYQVEYAMEAIGHAGTCLGILANDGVLLAAERRNIHKLLDEVFFSEKIYKLNEDMACSVAGITSDANVLTNELRLIAQRYLLQYQEPIPCEQLVTALCDIKQAYTQFGGKRPFGVSLLYIGWDKHYGFQLYQSDPSGNYGGWKATCIGNNSAAAVSMLKQDYKEGEMTLKSALALAIKVLNKTMDVSKLSAEKVEIATLTRENGKTVIRVLKQKEVEQLIKKHEEEEAKAEREKKEKEQKEKDK

Entity 4 Entity 4 polymer

Description description	20S proteasome
Molecular weight formula_weight	27929.9 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

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

MSYDRAITVFSPDGHLFQVEYAQEAVKKGSTAVGVRGRDIVVLGVEKKSVAKLQDERTVRKICALDDNVCMAFAGLTADARIVINRARVECQSHRLTVEDPVTVEYITRYIASLKQRYTQSNGRRPFGISALIVGFDFDGTPRLYQTDPSGTYHAWKANAIGRGAKSVREFLEKNYTDEAIETDDLTIKLVIKALLEVVQSGGKNIELAVMRRDQSLKILNPEEIEKYVAEIEKEKEENEKKKQKKAS

Entity 5 Entity 5 polymer

Description description	20S proteasome
Molecular weight formula_weight	26494.0 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	E,S

MFLTRSEYDRGVNTFSPEGRLFQVEYDIEAIKLGSTAIGIQTSEGVCLAVEKRITSPLMEPSSIEKIVEIDAHIGCAMSGLIADAKTLIDKARVETQNHWFTYNETMTVESVTQAVSNLALQFGEEDADPGAMSRPFGVALLFGGVDEKGPQLFHMDPSGTFVQCDARAIGSASEGAQSSLQELYHKSMTLKEAIKSSLIILKQVMEEKLNATNIELATVQPGQNFHMFTKEELEEVIKDI

Entity 6 Entity 6 polymer

Description description	20S proteasome
Molecular weight formula_weight	29595.6 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	F,T

MFRNQYDNDVTVWSPQGRIHQIEYAMEAVKQGSATVGLKSKTHAVLVALKRAQSELAAHQKKILHVDNHIGISIAGLTADARLLCNFMRQECLDSRFVFDRPLPVSRLVSLIGSKTQIPTQRYGRRPYGVGLLIAGYDDMGPHIFQTCPSANYFDCRAMSIGARSQSARTYLERHMSEFMECNLNELVKHGLRALRETLPAEQDLTTKNVSIGIVGKDLEFTIYDDDDVSPFLEGLEERPQRKAQPAQPADEPAEKADEPMEH

Entity 7 Entity 7 polymer

Description description	20S proteasome
Molecular weight formula_weight	28338.1 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	G,U

SSIGTGYDLSASTFSPDGRVFQVEYAMKAVENSSTAIGIRCKDGVVFGVEKLVLSKLYEEGSNKRLFNVDRHVGMAVAGLLADARSLADIAREEASNFRSNFGYNIPLKHLADRVAMYVHAYTLYSAVRPFGCSFMLGSYSVNDGAQLYMIDPSGVSYGYWGCAIGKARQAAKTEIEKLQMKEMTCRDIVKEVAKIIYIVHDEVKDKAFELELSWVGELTNGRHEIVPKDIREEAEKYAKESLKEEDESDDDNM

Entity 8 Entity 8 polymer

Description description	20S proteasome
Molecular weight formula_weight	21921.8 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	H,V

TTIMAVQFDGGVVLGADSRTTTGSYIANRVTDKLTPIHDRIFCCRSGSAADTQAVADAVTYQLGFHSIELNEPPLVHTAASLFKEMCYRYREDLMAGIIIAGWDPQEGGQVYSVPMGGMMVRQSFAIGGSGSSYIYGYVDATYREGMTKEECLQFTANALALAMERDGSSGGVIRLAAIAESGVERQVLLGDQIPKFAVATLPPA

Entity 9 Entity 9 polymer

Description description	20S proteasome
Molecular weight formula_weight	25351.0 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	I,W

TTIAGVVYKDGIVLGADTRATEGMVVADKNCSKIHFISPNIYCCGAGTAADTDMTTQLISSNLELHSLSTGRLPRVVTANRMLKQMLFRYRGYIGAALVLGGVDVTGPHLYSIYPHGSTDKLPYVTMGSGSLAAMAVFEDKFRPDMEEEEAKNLVSEAIAAGIFNDLGSGSNIDLCVISKNKLDFLRPYTVPNKKGTRLGRYRCEKGTTAVLTEKITPLEIEVLEETVQTMDTS

Entity 10 Entity 10 polymer

Description description	20S proteasome
Molecular weight formula_weight	22954.9 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

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

MSIMSYNGGAVMAMKGKNCVAIAADRRFGIQAQLVTTDFQKIFPMGDRLYIGLAGLATDVQTVAQRLKFRLNLYELKEGRQIKPYTLMSMVANLLYEKRFGPYYTEPVIAGLDPKTFKPFICSLDLIGCPMVTDDFVVSGTCAEQMYGMCESLWEPNMDPDHLFETISQAMLNAVDRDAVSGMGVIVHIIEKDKITTRTLKARMD

Entity 11 Entity 11 polymer

Description description	20S proteasome
Molecular weight formula_weight	22864.3 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

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

MEYLIGIQGPDYVLVASDRVAASNIVQMKDDHDKMFKMSEKILLLCVGEAGDTVQFAEYIQKNVQLYKMRNGYELSPTAAANFTRRNLADCLRSRTPYHVNLLLAGYDEHEGPALYYMDYLAALAKAPFAAHGYGAFLTLSILDRYYTPTISRERAVELLRKCLEELQKRFILNLPTFSVRIIDKNGIHDLDNISFPKQGS

Entity 12 Entity 12 polymer

Description description	20S proteasome
Molecular weight formula_weight	22484.4 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	L,Z

TTTLAFKFRHGVIVAADSRATAGAYIASQTVKKVIEINPYLLGTMAGGAADCSFWERLLARQCRIYELRNKERISVAAASKLLANMVYQYKGMGLSMGTMICGWDKRGPGLYYVDSEGNRISGATFSVGSGSVYAYGVMDRGYSYDLEVEQAYDLARRAIYQATYRDAYSGGAVNLYHVREDGWIRVSSDNVADLHEKYSGSTP

Entity 13 Entity 13 polymer

Description description	20S proteasome
Molecular weight formula_weight	23579.0 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	M,1

RFSPYVFNGGTILAIAGEDFAIVASDTRLSEGFSIHTRDSPKCYKLTDKTVIGCSGFHGDCLTLTKIIEARLKMYKHSNNKAMTTGAIAAMLSTILYSRRFFPYYVYNIIGGLDEEGKGAVYSFDPVGSYQRDSFKAGGSASAMLQPLLDNQVGFKNMQNVEHVPLSLDRAMRLVKDVFISAAERDVYTGDALRICIVTKEGIREETVSLRKD

Entity 14 Entity 14 polymer

Description description	20S proteasome
Molecular weight formula_weight	24402.7 kDa
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	N,2

TQNPMVTGTSVLGVKFEGGVVIAADMLGSYGSLARFRNISRIMRVNNSTMLGASGDYADFQYLKQVLGQMVIDEELLGDGHSYSPRAIHSWLTRAMYSRRSKMNPLWNTMVIGGYADGESFLGYVDMLGVAYEAPSLATGYGAYLAQPLLREVLEKQPVLSQTEARDLVERCMRVLYYRDARSYNRFQTATVTEKGVEIEGPLSTETNWDIAHMISGFE

Entity 15 Entity 15 non-polymer

Description description	MAGNESIUM ION
Molecular weight formula_weight	24.3 kDa
Source method src_method	syn
Copy count entity_count	30

Entity 16 Entity 16 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	165

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6. Fold Classification (SCOP + CATH) 56 domains

SCOP 2.08 (28 domains)

Domain ID domain_id	d1iru1_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1iru2_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1irua_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1irub_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1iruc_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1irud_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1irue_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1iruf_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1irug_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1iruh_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1irui_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1iruj_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1iruk_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1irul_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1irum_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1irun_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1iruo_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1irup_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1iruq_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1irur_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1irus_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1irut_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1iruu_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1iruv_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1iruw_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1irux_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1iruy_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

Domain ID domain_id	d1iruz_
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.153 — Ntn hydrolase-like
Superfamily Superfamily superfamily	d.153.1 — N-terminal nucleophile aminohydrolases (Ntn hydrolases)
Family Family family	d.153.1.4 — Proteasome subunits

CATH v4.4 (28 domains)

Domain ID domain_id	1iru100
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iru200
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruA00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruB00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruC00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruD00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruE00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruF00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruG00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruH00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruI00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruJ00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruK00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruL00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruM00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruN00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruO00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruP00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruQ00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruR00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruS00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruT00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruU00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruV00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruW00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruX00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruY00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

Domain ID domain_id	1iruZ00
Class class	3 — Alpha Beta
Architecture architecture	60 — 4-Layer Sandwich
Topology topology	20 — Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1
Homologous superfamily homologous superfamily	10 — Aminohydrolase, N-terminal nucleophile (Ntn) domain

▶

Unit-cell length a length_a	316.700 Å
Unit-cell length b length_b	205.900 Å
Unit-cell length c length_c	116.000 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	2.750 Å
Low-resolution limit resolution_low	65.000 Å
R factor r_factor	0.2520
R_work r_work	0.2500
R_free r_free	0.2940

Crystal Structure of the mammalian 20S proteasome at 2.75 A resolution

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

20S proteasome

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

1iru__assembly_1__model_1

1iru__assembly_1__model_1 | I(q)

1iru__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 (16)

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 polymer

Polymer Polymer

Entity 5 Entity 5 polymer

Polymer Polymer

Entity 6 Entity 6 polymer

Polymer Polymer

Entity 7 Entity 7 polymer

Polymer Polymer

Entity 8 Entity 8 polymer

Polymer Polymer

Entity 9 Entity 9 polymer

Polymer Polymer

Entity 10 Entity 10 polymer

Polymer Polymer

Entity 11 Entity 11 polymer

Polymer Polymer

Entity 12 Entity 12 polymer

Polymer Polymer

Entity 13 Entity 13 polymer

Polymer Polymer

Entity 14 Entity 14 polymer

Polymer Polymer

Entity 15 Entity 15 non-polymer

Entity 16 Entity 16 water

6. Fold Classification (SCOP + CATH) 56 domains

SCOP 2.08 (28 domains)

CATH v4.4 (28 domains)

7. Citations (1)