1k32

Crystal structure of the tricorn protease

Method: X-RAY DIFFRACTION

▼

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

tricorn protease

Thermoplasma acidophilum

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 6	water × 6	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	TRI_THEAC
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–1045； UniProt 27–1071 Author chain B； PDBConstruct 1–1045； UniProt 27–1071 Author chain C； PDBConstruct 1–1045； UniProt 27–1071 Author chain D； PDBConstruct 1–1045； UniProt 27–1071 Author chain E； PDBConstruct 1–1045； UniProt 27–1071 Author chain F； PDBConstruct 1–1045； UniProt 27–1071

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.

▼

2. Structure Basics 2. Structure Basics

Entry ID entry_id	1k32
Deposition date deposition_date	2001-10-01
Structure title title	Crystal structure of the tricorn protease
Keywords keywords	protein degradation, substrate gating, serine protease, beta propeller, proteasome, HYDROLASE; HYDROLASE
Experimental Method method	X-RAY DIFFRACTION

▼

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.

1k32__assembly_1__model_1

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

Download this curve (.dat)

1k32__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1k32__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	60.15 Å
Rg (electron density)	59.56 Å
Total Rg	59.65 Å
Atom count	49062
Residues	6138
Excluded volume	869730 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1k32__assembly_1__model_1`	hexameric （6）	Success	4.1.3-1-20251215 (887e7ef)	View Download

▶

4. Crystallography and Experiment 4. Crystallography & Experiment

▶

5. Entities and Polymers Entities & Polymers (2)

Entity 1 Entity 1 polymer

Description description	tricorn protease
Molecular weight formula_weight	118680.1 kDa
EC 编号 ec_number	3.4.21.-
Source method src_method	man
Copy count entity_count	6

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,C,D,E,F
Atom count atom_count	51456

KTFKLHEMHGLCMPNLLLNPDIHGDRIIFVCCDDLWEHDLKSGSTRKIVSNLGVINNARFFPDGRKIAIRVMRGSSLNTADLYFYNGENGEIKRITYFSGKSTGRRMFTDVAGFDPDGNLIISTDAMQPFSSMTCLYRVENDGINFVPLNLGPATHILFADGRRVIGRNTFELPHWKGYRGGTRGKIWIEVNSGAFKKIVDMSTHVSSPVIVGHRIYFITDIDGFGQIYSTDLDGKDLRKHTSFTDYYPRHLNTDGRRILFSKGGSIYIFNPDTEKIEKIEIGDLESPEDRIISIPSKFAEDFSPLDGDLIAFVSRGQAFIQDVSGTYVLKVPEPLRIRYVRRGGDTKVAFIHGTREGDFLGIYDYRTGKAEKFEENLGNVFAMGVDRNGKFAVVANDRFEIMTVDLETGKPTVIERSREAMITDFTISDNSRFIAYGFPLKHGETDGYVMQAIHVYDMEGRKIFAATTENSHDYAPAFDADSKNLYYLSYRSLDPSPDRVVLNFSFEVVSKPFVIPLIPGSPNPTKLVPRSMTSEAGEYDLNDMYKRSSPINVDPGDYRMIIPLESSILIYSVPVHGEFAAYYQGAPEKGVLLKYDVKTRKVTEVKNNLTDLRLSADRKTVMVRKDDGKIYTFPLEKPEDERTVETDKRPLVSSIHEEFLQMYDEAWKLARDNYWNEAVAKEISERIYEKYRNLVPLCKTRYDLSNVIVEMQGEYRTSHSYEMGGTFTDKDPFRSGRIACDFKLDGDHYVVAKAYAGDYSNEGEKSPIFEYGIDPTGYLIEDIDGETVGAGSNIYRVLSEKAGTSARIRLSGKGGDKRDLMIDILDDDRFIRYRSWVEANRRYVHERSKGTIGYIHIPDMGMMGLNEFYRLFINESSYQGLIVDVRFNGGGFVSQLIIEKLMNKRIGYDNPRRGTLSPYPTNSVRGKIIAITNEYAGSDGDIFSFSFKKLGLGKLIGTRTWGGVVGITPKRRLIDGTVLTQPEFAFWFRDAGFGVENYGVDPDVEIEYAPHDYLSGKDPQIDYAIDALIEELRNWNEELPQRPS

Source Source

Source organism organism	Thermoplasma acidophilum
NCBI taxonomy ID ncbi_taxonomy_id	2303
Host organism host_organism	Escherichia coli BL21(DE3)

Entity 2 Entity 2 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	2394

▼

6. Fold Classification (SCOP + CATH) 54 domains

SCOP 2.08 (24 domains)

Domain ID domain_id	d1k32a1
Class class	b — All beta proteins
Fold Fold fold	b.36 — PDZ domain-like
Superfamily Superfamily superfamily	b.36.1 — PDZ domain-like
Family Family family	b.36.1.3 — Tail specific protease PDZ domain

Domain ID domain_id	d1k32a2
Class class	b — All beta proteins
Fold Fold fold	b.68 — 6-bladed beta-propeller
Superfamily Superfamily superfamily	b.68.7 — Tricorn protease N-terminal domain
Family Family family	b.68.7.1 — Tricorn protease N-terminal domain

Domain ID domain_id	d1k32a3
Class class	b — All beta proteins
Fold Fold fold	b.69 — 7-bladed beta-propeller
Superfamily Superfamily superfamily	b.69.9 — Tricorn protease domain 2
Family Family family	b.69.9.1 — Tricorn protease domain 2

Domain ID domain_id	d1k32a4
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.14 — ClpP/crotonase
Superfamily Superfamily superfamily	c.14.1 — ClpP/crotonase
Family Family family	c.14.1.2 — Tail specific protease, catalytic domain

Domain ID domain_id	d1k32b1
Class class	b — All beta proteins
Fold Fold fold	b.36 — PDZ domain-like
Superfamily Superfamily superfamily	b.36.1 — PDZ domain-like
Family Family family	b.36.1.3 — Tail specific protease PDZ domain

Domain ID domain_id	d1k32b2
Class class	b — All beta proteins
Fold Fold fold	b.68 — 6-bladed beta-propeller
Superfamily Superfamily superfamily	b.68.7 — Tricorn protease N-terminal domain
Family Family family	b.68.7.1 — Tricorn protease N-terminal domain

Domain ID domain_id	d1k32b3
Class class	b — All beta proteins
Fold Fold fold	b.69 — 7-bladed beta-propeller
Superfamily Superfamily superfamily	b.69.9 — Tricorn protease domain 2
Family Family family	b.69.9.1 — Tricorn protease domain 2

Domain ID domain_id	d1k32b4
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.14 — ClpP/crotonase
Superfamily Superfamily superfamily	c.14.1 — ClpP/crotonase
Family Family family	c.14.1.2 — Tail specific protease, catalytic domain

Domain ID domain_id	d1k32c1
Class class	b — All beta proteins
Fold Fold fold	b.36 — PDZ domain-like
Superfamily Superfamily superfamily	b.36.1 — PDZ domain-like
Family Family family	b.36.1.3 — Tail specific protease PDZ domain

Domain ID domain_id	d1k32c2
Class class	b — All beta proteins
Fold Fold fold	b.68 — 6-bladed beta-propeller
Superfamily Superfamily superfamily	b.68.7 — Tricorn protease N-terminal domain
Family Family family	b.68.7.1 — Tricorn protease N-terminal domain

Domain ID domain_id	d1k32c3
Class class	b — All beta proteins
Fold Fold fold	b.69 — 7-bladed beta-propeller
Superfamily Superfamily superfamily	b.69.9 — Tricorn protease domain 2
Family Family family	b.69.9.1 — Tricorn protease domain 2

Domain ID domain_id	d1k32c4
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.14 — ClpP/crotonase
Superfamily Superfamily superfamily	c.14.1 — ClpP/crotonase
Family Family family	c.14.1.2 — Tail specific protease, catalytic domain

Domain ID domain_id	d1k32d1
Class class	b — All beta proteins
Fold Fold fold	b.36 — PDZ domain-like
Superfamily Superfamily superfamily	b.36.1 — PDZ domain-like
Family Family family	b.36.1.3 — Tail specific protease PDZ domain

Domain ID domain_id	d1k32d2
Class class	b — All beta proteins
Fold Fold fold	b.68 — 6-bladed beta-propeller
Superfamily Superfamily superfamily	b.68.7 — Tricorn protease N-terminal domain
Family Family family	b.68.7.1 — Tricorn protease N-terminal domain

Domain ID domain_id	d1k32d3
Class class	b — All beta proteins
Fold Fold fold	b.69 — 7-bladed beta-propeller
Superfamily Superfamily superfamily	b.69.9 — Tricorn protease domain 2
Family Family family	b.69.9.1 — Tricorn protease domain 2

Domain ID domain_id	d1k32d4
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.14 — ClpP/crotonase
Superfamily Superfamily superfamily	c.14.1 — ClpP/crotonase
Family Family family	c.14.1.2 — Tail specific protease, catalytic domain

Domain ID domain_id	d1k32e1
Class class	b — All beta proteins
Fold Fold fold	b.36 — PDZ domain-like
Superfamily Superfamily superfamily	b.36.1 — PDZ domain-like
Family Family family	b.36.1.3 — Tail specific protease PDZ domain

Domain ID domain_id	d1k32e2
Class class	b — All beta proteins
Fold Fold fold	b.68 — 6-bladed beta-propeller
Superfamily Superfamily superfamily	b.68.7 — Tricorn protease N-terminal domain
Family Family family	b.68.7.1 — Tricorn protease N-terminal domain

Domain ID domain_id	d1k32e3
Class class	b — All beta proteins
Fold Fold fold	b.69 — 7-bladed beta-propeller
Superfamily Superfamily superfamily	b.69.9 — Tricorn protease domain 2
Family Family family	b.69.9.1 — Tricorn protease domain 2

Domain ID domain_id	d1k32e4
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.14 — ClpP/crotonase
Superfamily Superfamily superfamily	c.14.1 — ClpP/crotonase
Family Family family	c.14.1.2 — Tail specific protease, catalytic domain

Domain ID domain_id	d1k32f1
Class class	b — All beta proteins
Fold Fold fold	b.36 — PDZ domain-like
Superfamily Superfamily superfamily	b.36.1 — PDZ domain-like
Family Family family	b.36.1.3 — Tail specific protease PDZ domain

Domain ID domain_id	d1k32f2
Class class	b — All beta proteins
Fold Fold fold	b.68 — 6-bladed beta-propeller
Superfamily Superfamily superfamily	b.68.7 — Tricorn protease N-terminal domain
Family Family family	b.68.7.1 — Tricorn protease N-terminal domain

Domain ID domain_id	d1k32f3
Class class	b — All beta proteins
Fold Fold fold	b.69 — 7-bladed beta-propeller
Superfamily Superfamily superfamily	b.69.9 — Tricorn protease domain 2
Family Family family	b.69.9.1 — Tricorn protease domain 2

Domain ID domain_id	d1k32f4
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.14 — ClpP/crotonase
Superfamily Superfamily superfamily	c.14.1 — ClpP/crotonase
Family Family family	c.14.1.2 — Tail specific protease, catalytic domain

CATH v4.4 (30 domains)

Domain ID domain_id	1k32A01
Class class	2 — Mainly Beta
Architecture architecture	120 — 6 Propeller
Topology topology	10 — Neuraminidase
Homologous superfamily homologous superfamily	60 — Tricorn protease N-terminal domain

Domain ID domain_id	1k32A02
Class class	2 — Mainly Beta
Architecture architecture	130 — 7 Propeller
Topology topology	10 — Methylamine Dehydrogenase; Chain H
Homologous superfamily homologous superfamily	10 — YVTN repeat-like/Quinoprotein amine dehydrogenase

Domain ID domain_id	1k32A03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	750 — Transcription Regulator spoIIAA
Homologous superfamily homologous superfamily	44 —

Domain ID domain_id	1k32A04
Class class	2 — Mainly Beta
Architecture architecture	30 — Roll
Topology topology	42 — Pdz3 Domain
Homologous superfamily homologous superfamily	10 — PDZ domain

Domain ID domain_id	1k32A05
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	226 — 2-enoyl-CoA Hydratase; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — 2-enoyl-CoA Hydratase; Chain A, domain 1

Domain ID domain_id	1k32B01
Class class	2 — Mainly Beta
Architecture architecture	120 — 6 Propeller
Topology topology	10 — Neuraminidase
Homologous superfamily homologous superfamily	60 — Tricorn protease N-terminal domain

Domain ID domain_id	1k32B02
Class class	2 — Mainly Beta
Architecture architecture	130 — 7 Propeller
Topology topology	10 — Methylamine Dehydrogenase; Chain H
Homologous superfamily homologous superfamily	10 — YVTN repeat-like/Quinoprotein amine dehydrogenase

Domain ID domain_id	1k32B03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	750 — Transcription Regulator spoIIAA
Homologous superfamily homologous superfamily	44 —

Domain ID domain_id	1k32B04
Class class	2 — Mainly Beta
Architecture architecture	30 — Roll
Topology topology	42 — Pdz3 Domain
Homologous superfamily homologous superfamily	10 — PDZ domain

Domain ID domain_id	1k32B05
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	226 — 2-enoyl-CoA Hydratase; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — 2-enoyl-CoA Hydratase; Chain A, domain 1

Domain ID domain_id	1k32C01
Class class	2 — Mainly Beta
Architecture architecture	120 — 6 Propeller
Topology topology	10 — Neuraminidase
Homologous superfamily homologous superfamily	60 — Tricorn protease N-terminal domain

Domain ID domain_id	1k32C02
Class class	2 — Mainly Beta
Architecture architecture	130 — 7 Propeller
Topology topology	10 — Methylamine Dehydrogenase; Chain H
Homologous superfamily homologous superfamily	10 — YVTN repeat-like/Quinoprotein amine dehydrogenase

Domain ID domain_id	1k32C03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	750 — Transcription Regulator spoIIAA
Homologous superfamily homologous superfamily	44 —

Domain ID domain_id	1k32C04
Class class	2 — Mainly Beta
Architecture architecture	30 — Roll
Topology topology	42 — Pdz3 Domain
Homologous superfamily homologous superfamily	10 — PDZ domain

Domain ID domain_id	1k32C05
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	226 — 2-enoyl-CoA Hydratase; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — 2-enoyl-CoA Hydratase; Chain A, domain 1

Domain ID domain_id	1k32D01
Class class	2 — Mainly Beta
Architecture architecture	120 — 6 Propeller
Topology topology	10 — Neuraminidase
Homologous superfamily homologous superfamily	60 — Tricorn protease N-terminal domain

Domain ID domain_id	1k32D02
Class class	2 — Mainly Beta
Architecture architecture	130 — 7 Propeller
Topology topology	10 — Methylamine Dehydrogenase; Chain H
Homologous superfamily homologous superfamily	10 — YVTN repeat-like/Quinoprotein amine dehydrogenase

Domain ID domain_id	1k32D03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	750 — Transcription Regulator spoIIAA
Homologous superfamily homologous superfamily	44 —

Domain ID domain_id	1k32D04
Class class	2 — Mainly Beta
Architecture architecture	30 — Roll
Topology topology	42 — Pdz3 Domain
Homologous superfamily homologous superfamily	10 — PDZ domain

Domain ID domain_id	1k32D05
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	226 — 2-enoyl-CoA Hydratase; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — 2-enoyl-CoA Hydratase; Chain A, domain 1

Domain ID domain_id	1k32E01
Class class	2 — Mainly Beta
Architecture architecture	120 — 6 Propeller
Topology topology	10 — Neuraminidase
Homologous superfamily homologous superfamily	60 — Tricorn protease N-terminal domain

Domain ID domain_id	1k32E02
Class class	2 — Mainly Beta
Architecture architecture	130 — 7 Propeller
Topology topology	10 — Methylamine Dehydrogenase; Chain H
Homologous superfamily homologous superfamily	10 — YVTN repeat-like/Quinoprotein amine dehydrogenase

Domain ID domain_id	1k32E03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	750 — Transcription Regulator spoIIAA
Homologous superfamily homologous superfamily	44 —

Domain ID domain_id	1k32E04
Class class	2 — Mainly Beta
Architecture architecture	30 — Roll
Topology topology	42 — Pdz3 Domain
Homologous superfamily homologous superfamily	10 — PDZ domain

Domain ID domain_id	1k32E05
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	226 — 2-enoyl-CoA Hydratase; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — 2-enoyl-CoA Hydratase; Chain A, domain 1

Domain ID domain_id	1k32F01
Class class	2 — Mainly Beta
Architecture architecture	120 — 6 Propeller
Topology topology	10 — Neuraminidase
Homologous superfamily homologous superfamily	60 — Tricorn protease N-terminal domain

Domain ID domain_id	1k32F02
Class class	2 — Mainly Beta
Architecture architecture	130 — 7 Propeller
Topology topology	10 — Methylamine Dehydrogenase; Chain H
Homologous superfamily homologous superfamily	10 — YVTN repeat-like/Quinoprotein amine dehydrogenase

Domain ID domain_id	1k32F03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	750 — Transcription Regulator spoIIAA
Homologous superfamily homologous superfamily	44 —

Domain ID domain_id	1k32F04
Class class	2 — Mainly Beta
Architecture architecture	30 — Roll
Topology topology	42 — Pdz3 Domain
Homologous superfamily homologous superfamily	10 — PDZ domain

Domain ID domain_id	1k32F05
Class class	3 — Alpha Beta
Architecture architecture	90 — Alpha-Beta Complex
Topology topology	226 — 2-enoyl-CoA Hydratase; Chain A, domain 1
Homologous superfamily homologous superfamily	10 — 2-enoyl-CoA Hydratase; Chain A, domain 1

▶

Unit-cell length a length_a	95.860 Å
Unit-cell length b length_b	245.998 Å
Unit-cell length c length_c	159.040 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	105.30 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	12

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

Resolution resolution	2.000 Å
Low-resolution limit resolution_low	20.000 Å
R factor r_factor	—
R_work r_work	0.2450
R_free r_free	0.2635

Crystal structure of the tricorn protease

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

tricorn protease

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

1k32__assembly_1__model_1

1k32__assembly_1__model_1 | I(q)

1k32__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 (2)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 water

6. Fold Classification (SCOP + CATH) 54 domains

SCOP 2.08 (24 domains)

CATH v4.4 (30 domains)

7. Citations (1)

Crystal structure of the tricorn protease

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

tricorn protease

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

1k32__assembly_1__model_1

1k32__assembly_1__model_1 | I(q)

1k32__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 (2)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 water

6. Fold Classification (SCOP + CATH) 54 domains

SCOP 2.08 (24 domains)

CATH v4.4 (30 domains)

7. Citations (1)