2a8d

Haemophilus influenzae beta-carbonic anhydrase complexed with bicarbonate

Method: X-RAY DIFFRACTION

▼

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

Carbonic anhydrase 2

Haemophilus influenzae

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 4	ZINC ION × 4 BICARBONATE ION × 4 SULFATE ION × 4 water × 4	Consistent with protein count
2	Protein homooligomer	Homooligomer	Protein 4	ZINC ION × 4 BICARBONATE ION × 4 SULFATE ION × 4 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	CAN_HAEIN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–229； UniProt 1–229 Author chain B； PDBConstruct 1–229； UniProt 1–229 Author chain C； PDBConstruct 1–229； UniProt 1–229 Author chain D； PDBConstruct 1–229； UniProt 1–229 Author chain E； PDBConstruct 1–229； UniProt 1–229 Author chain F； PDBConstruct 1–229； UniProt 1–229

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	2a8d
Deposition date deposition_date	2005-07-07
Structure title title	Haemophilus influenzae beta-carbonic anhydrase complexed with bicarbonate
Keywords keywords	x-ray structure; carbonic anhydrase; protein-bicarbonate complex, LYASE; LYASE
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.

2a8d__assembly_1__model_1

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

Download this curve (.dat)

2a8d__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

2a8d__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	28.63 Å
Rg (electron density)	27.54 Å
Total Rg	28.30 Å
Atom count	7070
Residues	873
Excluded volume	125310 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`2a8d__assembly_1__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`2a8d__assembly_2__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download

▶

4. Crystallography and Experiment 4. Crystallography & Experiment

▶

5. Entities and Polymers Entities & Polymers (5)

Entity 1 Entity 1 polymer

Description description	Carbonic anhydrase 2
Molecular weight formula_weight	26287.0 kDa
EC 编号 ec_number	4.2.1.1
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	10968

MDKIKQLFANNYSWAQRMKEENSTYFKELADHQTPHYLWIGCSDSRVPAEKLTNLEPGELFVHRNVANQVIHTDFNCLSVVQYAVDVLKIEHIIICGHTNCGGIHAAMADKDLGLINNWLLHIRDIWFKHGHLLGKLSPEKRADMLTKINVAEQVYNLGRTSIVKSAWERGQKLSLHGWVYDVNDGFLVDQGVMATSRETLEISYRNAIARLSILDEENILKKDHLENT

Source Source

Source organism organism	Haemophilus influenzae
NCBI taxonomy ID ncbi_taxonomy_id	727
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 non-polymer

Description description	ZINC ION
Molecular weight formula_weight	65.4 kDa
Source method src_method	syn
Copy count entity_count	6

Entity 3 Entity 3 non-polymer

Description description	BICARBONATE ION
Molecular weight formula_weight	61.0 kDa
Source method src_method	syn
Copy count entity_count	6

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	6

Entity 5 Entity 5 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	318

▼

6. Fold Classification (SCOP + CATH) 12 domains

SCOP 2.08 (6 domains)

Domain ID domain_id	d2a8da_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.53 — Resolvase-like
Superfamily Superfamily superfamily	c.53.2 — beta-carbonic anhydrase, cab
Family Family family	c.53.2.1 — beta-carbonic anhydrase, cab

Domain ID domain_id	d2a8db_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.53 — Resolvase-like
Superfamily Superfamily superfamily	c.53.2 — beta-carbonic anhydrase, cab
Family Family family	c.53.2.1 — beta-carbonic anhydrase, cab

Domain ID domain_id	d2a8dc_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.53 — Resolvase-like
Superfamily Superfamily superfamily	c.53.2 — beta-carbonic anhydrase, cab
Family Family family	c.53.2.1 — beta-carbonic anhydrase, cab

Domain ID domain_id	d2a8dd_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.53 — Resolvase-like
Superfamily Superfamily superfamily	c.53.2 — beta-carbonic anhydrase, cab
Family Family family	c.53.2.1 — beta-carbonic anhydrase, cab

Domain ID domain_id	d2a8de_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.53 — Resolvase-like
Superfamily Superfamily superfamily	c.53.2 — beta-carbonic anhydrase, cab
Family Family family	c.53.2.1 — beta-carbonic anhydrase, cab

Domain ID domain_id	d2a8df_
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.53 — Resolvase-like
Superfamily Superfamily superfamily	c.53.2 — beta-carbonic anhydrase, cab
Family Family family	c.53.2.1 — beta-carbonic anhydrase, cab

CATH v4.4 (6 domains)

Domain ID domain_id	2a8dA00
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	1050 — Beta-carbonic Anhydrase; Chain A
Homologous superfamily homologous superfamily	10 — Carbonic anhydrase

Domain ID domain_id	2a8dB00
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	1050 — Beta-carbonic Anhydrase; Chain A
Homologous superfamily homologous superfamily	10 — Carbonic anhydrase

Domain ID domain_id	2a8dC00
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	1050 — Beta-carbonic Anhydrase; Chain A
Homologous superfamily homologous superfamily	10 — Carbonic anhydrase

Domain ID domain_id	2a8dD00
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	1050 — Beta-carbonic Anhydrase; Chain A
Homologous superfamily homologous superfamily	10 — Carbonic anhydrase

Domain ID domain_id	2a8dE00
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	1050 — Beta-carbonic Anhydrase; Chain A
Homologous superfamily homologous superfamily	10 — Carbonic anhydrase

Domain ID domain_id	2a8dF00
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	1050 — Beta-carbonic Anhydrase; Chain A
Homologous superfamily homologous superfamily	10 — Carbonic anhydrase

▶

Unit-cell length a length_a	232.807 Å
Unit-cell length b length_b	144.602 Å
Unit-cell length c length_c	52.101 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	94.10 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	24

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	30.000 Å
R factor r_factor	0.2061
R_work r_work	0.2060
R_free r_free	0.2400

Haemophilus influenzae beta-carbonic anhydrase complexed with bicarbonate

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

Carbonic anhydrase 2

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

2a8d__assembly_1__model_1

2a8d__assembly_1__model_1 | I(q)

2a8d__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 non-polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 water

6. Fold Classification (SCOP + CATH) 12 domains

SCOP 2.08 (6 domains)

CATH v4.4 (6 domains)

7. Citations (1)

Haemophilus influenzae beta-carbonic anhydrase complexed with bicarbonate

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

Carbonic anhydrase 2

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

2a8d__assembly_1__model_1

2a8d__assembly_1__model_1 | I(q)

2a8d__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 non-polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

Entity 5 Entity 5 water

6. Fold Classification (SCOP + CATH) 12 domains

SCOP 2.08 (6 domains)

CATH v4.4 (6 domains)

7. Citations (1)