SAXSdb — 7a5x

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

Sialidase A

Streptococcus pneumoniae

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 2	;(4~{S},5~{R},6~{R})-5-acetamido-6-[(1~{R},2~{S})-3-[[1-(2-ethoxyethyl)-1,2,3-triazol-4-yl]methylsulfanyl]-1,2-bis(oxidanyl)propyl]-4-oxidanyl-oxane-2-carboxylic acid ; × 2 SULFATE ION × 2 CHLORIDE ION × 4 CALCIUM ION × 2 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	NANA_STREE
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 25–498； UniProt 318–791 Author chain B； PDBConstruct 25–498； UniProt 318–791

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	7a5x
Deposition date deposition_date	2020-08-24
Structure title title	Two copies of the catalytic domain of NanA sialidase from Streptococcus pneumoniae juxtaposed in the P212121 space group, in complex with DANA derivatized with a PEG linker on the glycerol group.
Keywords keywords	Sialidase, Catalytic domain, CA170, STRUCTURAL PROTEIN; STRUCTURAL PROTEIN
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.

7a5x__assembly_1__model_1

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

Download this curve (.dat)

7a5x__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

7a5x__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	32.27 Å
Rg (electron density)	31.72 Å
Total Rg	32.28 Å
Atom count	14831
Residues	944
Excluded volume	132880 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`7a5x__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 (6)

Entity 1 Entity 1 polymer

Description description	Sialidase A
Molecular weight formula_weight	56141.6 kDa
EC 编号 ec_number	3.2.1.18
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B
Atom count atom_count	15685

MGHHHHHHHHHHSSGHIDDDDKHMPEGAALTEKTDIFESGRNGKPNKDGIKSYRIPALLKTDKGTLIAGADERRLHSSDWGDIGMVIRRSEDNGKTWGDRVTITNLRDNPKASDPSIGSPVNIDMVLVQDPETKRIFSIYDMFPEGKGIFGMSSQKEEAYKKIDGKTYQILYREGEKGAYTIRENGTVYTPDGKATDYRVVVDPVKPAYSDKGDLYKGNQLLGNIYFTTNKTSPFRIAKDSYLWMSYSDDDGKTWSAPQDITPMVKADWMKFLGVGPGTGIVLRNGPHKGRILIPVYTTNNVSHLNGSQSSRIIYSDDHGKTWHAGEAVNDNRQVDGQKIHSSTMNNRRAQNTESTVVQLNNGDVKLFMRGLTGDLQVATSKDGGVTWEKDIKRYPQVKDVYVQMSAIHTMHEGKEYIILSNAGGPKRENGMVHLARVEENGELTWLKHNPIQKGEFAYNSLQELGNGEYGILYEHTEKGQNAYTLSFRKFNWDFLSK

Source Source

Source organism organism	Streptococcus pneumoniae
NCBI taxonomy ID ncbi_taxonomy_id	1313
Host organism host_organism	Escherichia coli BL21(DE3)

Entity 2 Entity 2 non-polymer

Description description	;(4~{S},5~{R},6~{R})-5-acetamido-6-[(1~{R},2~{S})-3-[[1-(2-ethoxyethyl)-1,2,3-triazol-4-yl]methylsulfanyl]-1,2-bis(oxidanyl)propyl]-4-oxidanyl-oxane-2-carboxylic acid ;
Molecular weight formula_weight	462.5 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 3 Entity 3 non-polymer

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

Entity 4 Entity 4 non-polymer

Description description	CHLORIDE ION
Molecular weight formula_weight	35.5 kDa
Source method src_method	syn
Copy count entity_count	4

Entity 5 Entity 5 non-polymer

Description description	CALCIUM ION
Molecular weight formula_weight	40.1 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 6 Entity 6 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	746

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Unit-cell length a length_a	49.203 Å
Unit-cell length b length_b	96.741 Å
Unit-cell length c length_c	226.381 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	orthorhombic

Resolution resolution	1.940 Å
Low-resolution limit resolution_low	56.600 Å
R factor r_factor	0.1912
R_work r_work	0.1888
R_free r_free	0.2379

Two copies of the catalytic domain of NanA sialidase from Streptococcus pneumoniae juxtaposed in the P212121 space group, in complex with DANA derivatized with a PEG linker on the glycerol group.

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

Sialidase A

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

7a5x__assembly_1__model_1

7a5x__assembly_1__model_1 | I(q)

7a5x__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 (6)

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 non-polymer

Entity 6 Entity 6 water

7. Citations (2)

Two copies of the catalytic domain of NanA sialidase from Streptococcus pneumoniae juxtaposed in the P212121 space group, in complex with DANA derivatized with a PEG linker on the glycerol group.

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

Sialidase A

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

7a5x__assembly_1__model_1

7a5x__assembly_1__model_1 | I(q)

7a5x__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 (6)

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 non-polymer

Entity 6 Entity 6 water

7. Citations (2)