SAXSdb — 2b6n

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

proteinase K

Serratia sp.

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	TRIPEPTIDE × 1 CALCIUM ION × 1 SULFATE ION × 2 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	Q3HUQ2_9ENTR
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–278； UniProt 127–404

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	2b6n
Deposition date deposition_date	2005-10-03
Structure title title	The 1.8 A crystal structure of a Proteinase K like enzyme from a psychrotroph Serratia species
Keywords keywords	S binding, substrate specificity, proteinase K, subtilase, psychrotrophic, psychrophilic, 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.

2b6n__assembly_1__model_1

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

Download this curve (.dat)

2b6n__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

2b6n__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	17.98 Å
Rg (electron density)	16.69 Å
Total Rg	17.60 Å
Atom count	2021
Residues	281
Excluded volume	34940 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`2b6n__assembly_1__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 (5)

Entity 1 Entity 1 polymer

Description description	proteinase K
Molecular weight formula_weight	28322.6 kDa
EC 编号 ec_number	3.4.21.-
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A
Atom count atom_count	2239

ADQPSPTWGIDRIDQRNLPLDNNYHTDYDGSGVTAFVIDTGVLNTHNEFGGRASSGYDFIDNDYDATDCNGHGTHVAGTIGGSTYGVAKNVNVVGVRVLNCSGSGSNSGVIAGINWVKNNASGPAVANMSLGGGASQATDDAVNAAVAAGITFVVAAGNDNSNACNYSPARAADAITVGSTTSNDSRSSFSNYGTCLDIYAPGSSITSSWYTSNSATNTISGTSMASPHVAGVAALYLDENPNLSPAQVTNLLKTRATADKVTDAKTGSPNKLLFSLA

Source Source

Source organism organism	Serratia sp.
NCBI taxonomy ID ncbi_taxonomy_id	348903
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 polymer

Description description	TRIPEPTIDE
Molecular weight formula_weight	287.3 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B

APT

Source Source

Source organism organism	Serratia sp.
NCBI taxonomy ID ncbi_taxonomy_id	348903
Host organism host_organism	Escherichia coli

Entity 3 Entity 3 non-polymer

Description description	CALCIUM ION
Molecular weight formula_weight	40.1 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 4 Entity 4 non-polymer

Description description	SULFATE ION
Molecular weight formula_weight	96.1 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 5 Entity 5 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	209

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6. Fold Classification (SCOP + CATH) 2 domains

SCOP 2.08 (1 domains)

Domain ID domain_id	d2b6na_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.41 — Subtilisin-like
Superfamily Superfamily superfamily	c.41.1 — Subtilisin-like
Family Family family	c.41.1.0 — automated matches

CATH v4.4 (1 domains)

Domain ID domain_id	2b6nA00
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	200 — Peptidase S8/S53 domain

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Unit-cell length a length_a	86.430 Å
Unit-cell length b length_b	42.560 Å
Unit-cell length c length_c	74.260 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	110.19 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	4

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

Resolution resolution	1.800 Å
Low-resolution limit resolution_low	23.760 Å
R factor r_factor	0.1630
R_work r_work	0.1600
R_free r_free	0.1940

The 1.8 A crystal structure of a Proteinase K like enzyme from a psychrotroph Serratia species

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

proteinase K

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

2b6n__assembly_1__model_1

2b6n__assembly_1__model_1 | I(q)

2b6n__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 (5)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 water

6. Fold Classification (SCOP + CATH) 2 domains

SCOP 2.08 (1 domains)

CATH v4.4 (1 domains)

7. Citations (1)

The 1.8 A crystal structure of a Proteinase K like enzyme from a psychrotroph Serratia species

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

proteinase K

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

2b6n__assembly_1__model_1

2b6n__assembly_1__model_1 | I(q)

2b6n__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 (5)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 water

6. Fold Classification (SCOP + CATH) 2 domains

SCOP 2.08 (1 domains)

CATH v4.4 (1 domains)

7. Citations (1)