SAXSdb — 1xrb

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

S-ADENOSYLMETHIONINE SYNTHETASE

OrganismNot specified

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein homooligomer	Homooligomer	Protein 2	PHOSPHATE ION × 4 MAGNESIUM ION × 4 POTASSIUM ION × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	METK_ECOLI
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–383； UniProt 2–384

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	1xrb
Deposition date deposition_date	1995-10-26
Structure title title	S-adenosylmethionine synthetase (MAT, ATP: L-methionine S-adenosyltransferase, E.C.2.5.1.6) in which MET residues are replaced with selenomethionine residues (MSE)
Keywords keywords	METHYLTRANSFERASE, TRANSFERASE; TRANSFERASE
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.

1xrb__assembly_1__model_1

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

Download this curve (.dat)

1xrb__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1xrb__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	25.71 Å
Rg (electron density)	24.74 Å
Total Rg	25.54 Å
Atom count	7087
Residues	736
Excluded volume	103760 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1xrb__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 (4)

Entity 1 Entity 1 polymer

Description description	S-ADENOSYLMETHIONINE SYNTHETASE
Molecular weight formula_weight	42289.4 kDa
EC 编号 ec_number	2.5.1.6
Mutation mutation	MET RESIDUES ARE REPLACED WITH SELENOMETHIONINE
Source method src_method	nat
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A
Atom count atom_count	3544

AKHLFTSESVSEGHPDKIADQISDAVLDAILEQDPKARVACETYVKTGMVLVGGEITTSAWVDIEEITRNTVREIGYVHSDMGFDANSCAVLSAIGKQSPDINQGVDRADPLEQGAGDQGLMFGYATNETDVLMPAPITYAHRLVQRQAEVRKNGTLPWLRPDAKSQVTFQYDDGKIVGIDAVVLSTQHSEEIDQKSLQEAVMEEIIKPILPAEWLTSATKFFINPTGRFVIGGPMGDCGLTGRKIIVDTYGGMARHGGGAFSGKDPSKVDRSAAYAARYVAKNIVAAGLADRCEIQVSYAIGVAEPTSIMVETFGTEKVPSEQLTLLVREFFDLRPYGLIQMLDLLHPIYKETAAYGHFGREHFPWEKTDKAQLLRDAAGLK

Entity 2 Entity 2 non-polymer

Description description	PHOSPHATE ION
Molecular weight formula_weight	95.0 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 3 Entity 3 non-polymer

Description description	MAGNESIUM ION
Molecular weight formula_weight	24.3 kDa
Source method src_method	syn
Copy count entity_count	2

Entity 4 Entity 4 non-polymer

Description description	POTASSIUM ION
Molecular weight formula_weight	39.1 kDa
Source method src_method	syn
Copy count entity_count	2

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6. Fold Classification (SCOP + CATH) 6 domains

SCOP 2.08 (3 domains)

Domain ID domain_id	d1xrba1
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.130 — S-adenosylmethionine synthetase
Superfamily Superfamily superfamily	d.130.1 — S-adenosylmethionine synthetase
Family Family family	d.130.1.1 — S-adenosylmethionine synthetase

Domain ID domain_id	d1xrba2
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.130 — S-adenosylmethionine synthetase
Superfamily Superfamily superfamily	d.130.1 — S-adenosylmethionine synthetase
Family Family family	d.130.1.1 — S-adenosylmethionine synthetase

Domain ID domain_id	d1xrba3
Class class	d — Alpha and beta proteins (a+b)
Fold Fold fold	d.130 — S-adenosylmethionine synthetase
Superfamily Superfamily superfamily	d.130.1 — S-adenosylmethionine synthetase
Family Family family	d.130.1.1 — S-adenosylmethionine synthetase

CATH v4.4 (3 domains)

Domain ID domain_id	1xrbA01
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	300 — GMP Synthetase; Chain A, domain 3
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	1xrbA02
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	300 — GMP Synthetase; Chain A, domain 3
Homologous superfamily homologous superfamily	10 —

Domain ID domain_id	1xrbA03
Class class	3 — Alpha Beta
Architecture architecture	30 — 2-Layer Sandwich
Topology topology	300 — GMP Synthetase; Chain A, domain 3
Homologous superfamily homologous superfamily	10 —

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Unit-cell length a length_a	128.900 Å
Unit-cell length b length_b	128.900 Å
Unit-cell length c length_c	139.800 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.00 °
Unit-cell angle γ angle_gamma	120.00 °
Molecules per unit cell Z z_pdb	12

Space group space_group	P 62 2 2
Space-group number int_tables_number	180
Crystal system crystal_system	—

Resolution resolution	3.000 Å
Low-resolution limit resolution_low	10.000 Å
R factor r_factor	0.1880
R_work r_work	0.1880
R_free r_free	0.2650

S-adenosylmethionine synthetase (MAT, ATP: L-methionine S-adenosyltransferase, E.C.2.5.1.6) in which MET residues are replaced with selenomethionine residues (MSE)

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

S-ADENOSYLMETHIONINE SYNTHETASE

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

1xrb__assembly_1__model_1

1xrb__assembly_1__model_1 | I(q)

1xrb__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

5. Entities and Polymers Entities & Polymers (4)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

6. Fold Classification (SCOP + CATH) 6 domains

SCOP 2.08 (3 domains)

CATH v4.4 (3 domains)

7. Citations (1)

S-adenosylmethionine synthetase (MAT, ATP: L-methionine S-adenosyltransferase, E.C.2.5.1.6) in which MET residues are replaced with selenomethionine residues (MSE)

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

S-ADENOSYLMETHIONINE SYNTHETASE

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

1xrb__assembly_1__model_1

1xrb__assembly_1__model_1 | I(q)

1xrb__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

5. Entities and Polymers Entities & Polymers (4)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 non-polymer

6. Fold Classification (SCOP + CATH) 6 domains

SCOP 2.08 (3 domains)

CATH v4.4 (3 domains)

7. Citations (1)