2ffh

THE SIGNAL SEQUENCE BINDING PROTEIN FFH FROM THERMUS AQUATICUS

Method: X-RAY DIFFRACTION

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

PROTEIN (FFH)

Thermus aquaticus

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein monomer	Monomer	Protein 1	CADMIUM ION × 5 SULFATE ION × 1	Consistent with protein count
10	Protein homooligomer	Homooligomer	Protein 2	CADMIUM ION × 11 SULFATE ION × 2	Consistent with protein count
2	Protein monomer	Monomer	Protein 1	CADMIUM ION × 4 SULFATE ION × 1	Consistent with protein count
3	Protein monomer	Monomer	Protein 1	CADMIUM ION × 7 SULFATE ION × 1	Consistent with protein count
4	Protein homooligomer	Homooligomer	Protein 9	CADMIUM ION × 48 SULFATE ION × 9	Consistent with protein count
5	Protein homooligomer	Homooligomer	Protein 6	CADMIUM ION × 32 SULFATE ION × 6	Consistent with protein count
6	Protein homooligomer	Homooligomer	Protein 6	CADMIUM ION × 32 SULFATE ION × 6	Consistent with protein count
7	Protein homooligomer	Homooligomer	Protein 3	CADMIUM ION × 16 SULFATE ION × 3	Consistent with protein count
8	Protein homooligomer	Homooligomer	Protein 2	CADMIUM ION × 14 SULFATE ION × 2	Consistent with protein count
9	Protein homooligomer	Homooligomer	Protein 2	CADMIUM ION × 9 SULFATE ION × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	SRP54_THEAQ
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–425； UniProt 1–425 Author chain B； PDBConstruct 1–425； UniProt 1–425 Author chain C； PDBConstruct 1–425； UniProt 1–425

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	2ffh
Deposition date deposition_date	1999-06-29
Structure title title	THE SIGNAL SEQUENCE BINDING PROTEIN FFH FROM THERMUS AQUATICUS
Keywords keywords	;FFH, SRP54, SIGNAL RECOGNITION PARTICLE, GTPASE, M DOMAIN, RNA-BINDING, SIGNAL SEQUENCE-BINDING, HELIX-TURN-HELIX, PROTEIN TARGETING, PROTEIN TRANSPORT ;; PROTEIN TRANSPORT
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.

2ffh__assembly_5__model_1

Assembly 5 · Model 1 · CRYSOL 4.1.3-1-20251215 (887e7ef)

Download this curve (.dat)

2ffh__assembly_5__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

2ffh__assembly_5__model_1 | P(r) · Pending

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

Rg（Guinier）	44.09 Å
Rg (electron density)	43.43 Å
Total Rg	43.68 Å
Atom count	18968
Residues	2442
Excluded volume	341810 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`2ffh__assembly_1__model_1`	monomeric （1）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`2ffh__assembly_2__model_1`	monomeric （1）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`2ffh__assembly_3__model_1`	monomeric （1）	Success	4.1.3-1-20251215 (887e7ef)	View Download
4	1	`2ffh__assembly_4__model_1`	nonameric （9）	Success	4.1.3-1-20251215 (887e7ef)	View Download
5	1	`2ffh__assembly_5__model_1`	hexameric （6）	Success	4.1.3-1-20251215 (887e7ef)	View Download
6	1	`2ffh__assembly_6__model_1`	hexameric （6）	Success	4.1.3-1-20251215 (887e7ef)	View Download
7	1	`2ffh__assembly_7__model_1`	trimeric （3）	Success	4.1.3-1-20251215 (887e7ef)	View Download
8	1	`2ffh__assembly_8__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
9	1	`2ffh__assembly_9__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
10	1	`2ffh__assembly_10__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 (3)

Entity 1 Entity 1 polymer

Description description	PROTEIN (FFH)
Molecular weight formula_weight	46811.4 kDa
Mutation mutation	A48T
Source method src_method	man
Copy count entity_count	3

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,B,C
Atom count atom_count	9484

MFQQLSARLQEAIGRLRGRGRITEEDLKATLREIRRALMDADVNLEVTRDFVERVREEALGKQVLESLTPAEVILATVYEALKEALGGEARLPVLKDRNLWFLVGLQGSGKTTTAAKLALYYKGKGRRPLLVAADTQRPAAREQLRLLGEKVGVPVLEVMDGESPESIRRRVEEKARLEARDLILVDTAGRLQIDEPLMGELARLKEVLGPDEVLLVLDAMTGQEALSVARAFDEKVGVTGLVLTKLDGDARGGAALSARHVTGKPIYFAGVSEKPEGLEPFYPERLAGRILGMGDVASLAEKVRAAGLEAEAPKSAKELSLEDFLKQMQNLKRLGPFSEILGLLPGVPQGLKVDEKAIKRLEAIVLSMTPEERKDPRILNGSRRKRIAKGSGTSVQEVNRFIKAFEEMKALMKSLEKKKGRGLM

Source Source

Source organism organism	Thermus aquaticus
NCBI taxonomy ID ncbi_taxonomy_id	271
Host organism host_organism	Escherichia coli

Entity 2 Entity 2 non-polymer

Description description	CADMIUM ION
Molecular weight formula_weight	112.4 kDa
Source method src_method	syn
Copy count entity_count	16

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	3

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6. Fold Classification (SCOP + CATH) 18 domains

SCOP 2.08 (9 domains)

Domain ID domain_id	d2ffha1
Class class	a — All alpha proteins
Fold Fold fold	a.24 — Four-helical up-and-down bundle
Superfamily Superfamily superfamily	a.24.13 — Domain of the SRP/SRP receptor G-proteins
Family Family family	a.24.13.1 — Domain of the SRP/SRP receptor G-proteins

Domain ID domain_id	d2ffha2
Class class	a — All alpha proteins
Fold Fold fold	a.36 — Signal peptide-binding domain
Superfamily Superfamily superfamily	a.36.1 — Signal peptide-binding domain
Family Family family	a.36.1.1 — Signal peptide-binding domain

Domain ID domain_id	d2ffha3
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.37 — P-loop containing nucleoside triphosphate hydrolases
Superfamily Superfamily superfamily	c.37.1 — P-loop containing nucleoside triphosphate hydrolases
Family Family family	c.37.1.10 — Nitrogenase iron protein-like

Domain ID domain_id	d2ffhb1
Class class	a — All alpha proteins
Fold Fold fold	a.24 — Four-helical up-and-down bundle
Superfamily Superfamily superfamily	a.24.13 — Domain of the SRP/SRP receptor G-proteins
Family Family family	a.24.13.1 — Domain of the SRP/SRP receptor G-proteins

Domain ID domain_id	d2ffhb2
Class class	a — All alpha proteins
Fold Fold fold	a.36 — Signal peptide-binding domain
Superfamily Superfamily superfamily	a.36.1 — Signal peptide-binding domain
Family Family family	a.36.1.1 — Signal peptide-binding domain

Domain ID domain_id	d2ffhb3
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.37 — P-loop containing nucleoside triphosphate hydrolases
Superfamily Superfamily superfamily	c.37.1 — P-loop containing nucleoside triphosphate hydrolases
Family Family family	c.37.1.10 — Nitrogenase iron protein-like

Domain ID domain_id	d2ffhc1
Class class	a — All alpha proteins
Fold Fold fold	a.24 — Four-helical up-and-down bundle
Superfamily Superfamily superfamily	a.24.13 — Domain of the SRP/SRP receptor G-proteins
Family Family family	a.24.13.1 — Domain of the SRP/SRP receptor G-proteins

Domain ID domain_id	d2ffhc2
Class class	a — All alpha proteins
Fold Fold fold	a.36 — Signal peptide-binding domain
Superfamily Superfamily superfamily	a.36.1 — Signal peptide-binding domain
Family Family family	a.36.1.1 — Signal peptide-binding domain

Domain ID domain_id	d2ffhc3
Class class	c — Alpha and beta proteins (a/b)
Fold Fold fold	c.37 — P-loop containing nucleoside triphosphate hydrolases
Superfamily Superfamily superfamily	c.37.1 — P-loop containing nucleoside triphosphate hydrolases
Family Family family	c.37.1.10 — Nitrogenase iron protein-like

CATH v4.4 (9 domains)

Domain ID domain_id	2ffhA01
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	120 — Four Helix Bundle (Hemerythrin (Met), subunit A)
Homologous superfamily homologous superfamily	140 — SRP54, nucleotide-binding domain

Domain ID domain_id	2ffhA02
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	300 — P-loop containing nucleotide triphosphate hydrolases

Domain ID domain_id	2ffhA03
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	260 — 434 Repressor (Amino-terminal Domain)
Homologous superfamily homologous superfamily	30 — Signal recognition particle, SRP54 subunit, M-domain

Domain ID domain_id	2ffhB01
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	120 — Four Helix Bundle (Hemerythrin (Met), subunit A)
Homologous superfamily homologous superfamily	140 — SRP54, nucleotide-binding domain

Domain ID domain_id	2ffhB02
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	300 — P-loop containing nucleotide triphosphate hydrolases

Domain ID domain_id	2ffhB03
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	260 — 434 Repressor (Amino-terminal Domain)
Homologous superfamily homologous superfamily	30 — Signal recognition particle, SRP54 subunit, M-domain

Domain ID domain_id	2ffhC01
Class class	1 — Mainly Alpha
Architecture architecture	20 — Up-down Bundle
Topology topology	120 — Four Helix Bundle (Hemerythrin (Met), subunit A)
Homologous superfamily homologous superfamily	140 — SRP54, nucleotide-binding domain

Domain ID domain_id	2ffhC02
Class class	3 — Alpha Beta
Architecture architecture	40 — 3-Layer(aba) Sandwich
Topology topology	50 — Rossmann fold
Homologous superfamily homologous superfamily	300 — P-loop containing nucleotide triphosphate hydrolases

Domain ID domain_id	2ffhC03
Class class	1 — Mainly Alpha
Architecture architecture	10 — Orthogonal Bundle
Topology topology	260 — 434 Repressor (Amino-terminal Domain)
Homologous superfamily homologous superfamily	30 — Signal recognition particle, SRP54 subunit, M-domain

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Unit-cell length a length_a	195.050 Å
Unit-cell length b length_b	195.050 Å
Unit-cell length c length_c	335.720 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	54

Space group space_group	H 3 2
Space-group number int_tables_number	155
Crystal system crystal_system	—

Resolution resolution	3.200 Å
Low-resolution limit resolution_low	30.000 Å
R factor r_factor	—
R_work r_work	0.2570
R_free r_free	0.2960

THE SIGNAL SEQUENCE BINDING PROTEIN FFH FROM THERMUS AQUATICUS

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

PROTEIN (FFH)

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

2ffh__assembly_5__model_1

2ffh__assembly_5__model_1 | I(q)

2ffh__assembly_5__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 (3)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 non-polymer

6. Fold Classification (SCOP + CATH) 18 domains

SCOP 2.08 (9 domains)

CATH v4.4 (9 domains)

7. Citations (2)

THE SIGNAL SEQUENCE BINDING PROTEIN FFH FROM THERMUS AQUATICUS

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

PROTEIN (FFH)

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

2ffh__assembly_5__model_1

2ffh__assembly_5__model_1 | I(q)

2ffh__assembly_5__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 (3)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 non-polymer

Entity 3 Entity 3 non-polymer

6. Fold Classification (SCOP + CATH) 18 domains

SCOP 2.08 (9 domains)

CATH v4.4 (9 domains)

7. Citations (2)