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3ihq

Crystal Structure of Reduced C10S Spx in Complex with the Alpha C-terminal Domain of RNA Polymeras

Method: X-RAY DIFFRACTION Dmax: 61.5 Å Quality: GOOD
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1. Protein Identity and Related Structures Protein Identity & Related Structures

Regulatory protein spx

Bacillus subtilis

UniProt O31602

State in the Current Structure

Assembly Oligomeric State Construct Mutations and Modifications Ligands, Ions and Associated Components Method and Experimental Conditions Structure Quality
1 Protein heterocomplex Heteromer Protein × 2 PDB declaration: dimeric（2） Consistent with protein copy count Chain A； UniProt 1–131 Mutation：C10S DNA-directed RNA polymerase subunit alpha × 1 （P20429） IMD IMIDAZOLE × 1 X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, HANGING DROP；pH 5.3；273 K；25-30% PEG 4000, 0.1 M sodium citrate, 0.1 M magnesium chloride, pH 5.3, VAPOR DIFFUSION, HANGING DROP, temperature 273K Resolution 1.90 Å R-free 0.278

Other States of the Same Protein in the Database

Each row is a biological assembly of the same UniProt protein in another PDB entry. The “Difference from current entry” column identifies evidence-level differences; no tag means the currently parsed fields agree.

Other PDB Difference from Current Entry 3IHQ Assembly / Oligomeric State Construct Mutations and Modifications Ligands, Ions and Non-polymers Method and Experimental Conditions Structure Quality
1Z3E Crystal Structure of Spx in Complex with the C-terminal Domain of the RNA Polymerase Alpha Subunit Deposited 2005-03-11 Different construct Different mutation/modification Different ligand/ion Different experimental conditions Different structure-quality metrics Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric
Chain A 1–131（131 aa） Fragment：transcription regulator
Not recorded SO4 SULFATE ION × 4 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION；pH 5.6；273 K；lithium sulfate, ammonium sulfate, sodium citrate, pH 5.6, VAPOR DIFFUSION, temperature 273K
Resolution 1.50 Å R-free 0.220
3GFK Crystal structure of Bacillus subtilis Spx/RNA polymerase alpha subunit C-terminal domain complex Deposited 2009-02-27 Different mutation/modification Different ligand/ion Different experimental conditions Different structure-quality metrics Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric
Chain A 1–131（131 aa）
Not recorded No recorded non-water small molecule X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION；pH 5；295 K；vapor diffusion against 6% (w/v) PEG 6000, 100 mM sodium acetate, pH 5.0, 10 micromolar CuCl2, protein concentration 11.5 mg/mL, temperature 295K
Resolution 2.30 Å R-free 0.282
6GHB Crystal structure of Spx in complex with YjbH (oxidized) Deposited 2018-05-06 Different mutation/modification Different ligand/ion Different experimental conditions Different structure-quality metrics Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric
Chain A 1–131（131 aa）
Not recorded MG MAGNESIUM ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7.5；293 K；Na-HEPES pH 7.5, MgCl2 and PEG400
Resolution 3.10 Å R-free 0.266
6GHB Crystal structure of Spx in complex with YjbH (oxidized) Deposited 2018-05-06 Different mutation/modification Different ligand/ion Different experimental conditions Different structure-quality metrics Assembly 2 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric
Chain C 1–131（131 aa）
Not recorded MG MAGNESIUM ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 7.5；293 K；Na-HEPES pH 7.5, MgCl2 and PEG400
Resolution 3.10 Å R-free 0.266
6GHO Crystal structure of Spx in complex with YjbH Deposited 2018-05-08 Different mutation/modification Different ligand/ion Different experimental conditions Different structure-quality metrics Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric
Chain A 1–131（131 aa）
Not recorded CL CHLORIDE ION × 1 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION, HANGING DROP；pH 6；293 K；PEG 3350, MgCl2 and Bis-Tris pH 6.0
Resolution 1.79 Å R-free 0.221

4 other PDB entries and 5 assemblies. Open the comparison page and filter oligomeric states

View Construct and Data Evidence
UniProt name SPX_BACSU
Isoform —
PDB entities 1
Chains and sequence ranges Author chain A； PDBConstruct 2–132； UniProt 1–131

DNA-directed RNA polymerase subunit alpha

Bacillus subtilis

UniProt P20429

State in the Current Structure

Assembly Oligomeric State Construct Mutations and Modifications Ligands, Ions and Associated Components Method and Experimental Conditions Structure Quality
1 Protein heterocomplex Heteromer Protein × 2 PDB declaration: dimeric（2） Consistent with protein copy count Chain B； UniProt 245–314 Fragment：UNP residues 245-314 Regulatory protein spx × 1 （O31602） IMD IMIDAZOLE × 1 X-RAY DIFFRACTION X-ray crystallization conditions：VAPOR DIFFUSION, HANGING DROP；pH 5.3；273 K；25-30% PEG 4000, 0.1 M sodium citrate, 0.1 M magnesium chloride, pH 5.3, VAPOR DIFFUSION, HANGING DROP, temperature 273K Resolution 1.90 Å R-free 0.278

Other States of the Same Protein in the Database

Each row is a biological assembly of the same UniProt protein in another PDB entry. The “Difference from current entry” column identifies evidence-level differences; no tag means the currently parsed fields agree.

Other PDB Difference from Current Entry 3IHQ Assembly / Oligomeric State Construct Mutations and Modifications Ligands, Ions and Non-polymers Method and Experimental Conditions Structure Quality
1Z3E Crystal Structure of Spx in Complex with the C-terminal Domain of the RNA Polymerase Alpha Subunit Deposited 2005-03-11 Different construct Different ligand/ion Different experimental conditions Different structure-quality metrics Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric
Chain B 245–314（70 aa） Fragment：c-terminal domain of RNA polymerase alpha subunit
Not recorded SO4 SULFATE ION × 4 X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION；pH 5.6；273 K；lithium sulfate, ammonium sulfate, sodium citrate, pH 5.6, VAPOR DIFFUSION, temperature 273K
Resolution 1.50 Å R-free 0.220
3GFK Crystal structure of Bacillus subtilis Spx/RNA polymerase alpha subunit C-terminal domain complex Deposited 2009-02-27 Different construct Different ligand/ion Different experimental conditions Different structure-quality metrics Assembly 1 Protein heterocomplex Heteromer；Protein × 2 PDB declaration: dimeric
Chain B 240–314（75 aa） Fragment：Alpha C-terminal domain (alpha-CTD)
Not recorded No recorded non-water small molecule X-RAY DIFFRACTION
X-ray crystallization conditions VAPOR DIFFUSION；pH 5；295 K；vapor diffusion against 6% (w/v) PEG 6000, 100 mM sodium acetate, pH 5.0, 10 micromolar CuCl2, protein concentration 11.5 mg/mL, temperature 295K
Resolution 2.30 Å R-free 0.282
6WVJ Cryo-EM structure of Bacillus subtilis RNA Polymerase elongation complex Deposited 2020-05-06 Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics Assembly 1 Other combination Heteromer；Protein × 5 PDB declaration: octameric
Chain A 1–314（314 aa）
Chain B 1–314（314 aa）
Not recorded ZN ZINC ION × 2 MG MAGNESIUM ION × 1 ELECTRON MICROSCOPY
cryo-EM buffer pH 7.8
cryo-EM vitrification conditions Cryogen ETHANE；Sample loading volume ranged between 2 and 3 microlitres. Samples were blotted for 5 seconds prior to vitrification.
Resolution 3.36 Å
6WVK Cryo-EM structure of Bacillus subtilis RNA Polymerase in complex with HelD Deposited 2020-05-06 Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics Assembly 1 Protein heterocomplex Heteromer；Protein × 7 PDB declaration: heptameric
Chain A 1–314（314 aa）
Chain B 1–314（314 aa）
Not recorded ZN ZINC ION × 2 MG MAGNESIUM ION × 1 ELECTRON MICROSCOPY
cryo-EM buffer pH 7.8
cryo-EM vitrification conditions Cryogen ETHANE；Sample loading volume ranged between 2 and 3 microlitres. Samples were blotted for 5 seconds prior to vitrification.
Resolution 3.36 Å
7CKQ The cryo-EM structure of B. subtilis BmrR transcription activation complex Deposited 2020-07-18 Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics Assembly 1 Protein–DNA Heteromer；Protein × 9 PDB declaration: undecameric
Chain A 1–314（314 aa）
Chain B 1–314（314 aa）
Not recorded MG MAGNESIUM ION × 1 ZN ZINC ION × 2 P4P TETRAPHENYLPHOSPHONIUM × 2 ELECTRON MICROSCOPY
cryo-EM buffer pH 7.5
cryo-EM vitrification conditions Cryogen ETHANE
Resolution 4.40 Å
7F75 Cryo-EM structure of Spx-dependent transcription activation complex Deposited 2021-06-28 Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics Assembly 1 Protein–DNA Heteromer；Protein × 10 PDB declaration: dodecameric
Chain A 1–314（314 aa）
Chain B 1–314（314 aa）
Chain I 1–314（314 aa）
Not recorded MG MAGNESIUM ION × 1 ZN ZINC ION × 2 ELECTRON MICROSCOPY
cryo-EM buffer pH 7.5
cryo-EM vitrification conditions Cryogen ETHANE
Resolution 4.20 Å
8XA6 Cryo-EM structure of Bacillus RNAP and SPO1 gp33 complex Deposited 2023-12-02 Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric
Chain A 1–314（314 aa）
Chain B 1–314（314 aa）
Not recorded No recorded non-water small molecule ELECTRON MICROSCOPY
cryo-EM buffer pH 8
cryo-EM vitrification conditions Cryogen ETHANE
Resolution 3.02 Å
8XA7 Cryo-EM structure of Bacillus subtilis RNAP,sigA and SPO1 gp33 complex Deposited 2023-12-02 Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics Assembly 1 Protein heterocomplex Heteromer；Protein × 9 PDB declaration: nonameric
Chain A 1–314（314 aa）
Chain B 1–314（314 aa）
Not recorded No recorded non-water small molecule ELECTRON MICROSCOPY
cryo-EM buffer pH 8
cryo-EM vitrification conditions Cryogen ETHANE
Resolution 2.94 Å
8XA8 Cryo-EM structure of Bacillus RNAP and HelD complex Deposited 2023-12-02 Different construct Different mutation/modification Different oligomeric state Different ligand/ion Different experimental method Different experimental conditions Different structure-quality metrics Assembly 1 Protein heterocomplex Heteromer；Protein × 8 PDB declaration: octameric
Chain A 1–314（314 aa）
Chain B 1–314（314 aa）
Not recorded ZN ZINC ION × 2 MG MAGNESIUM ION × 1 ELECTRON MICROSCOPY
cryo-EM buffer pH 8
cryo-EM vitrification conditions Cryogen ETHANE
Resolution 3.19 Å

9 other PDB entries and 9 assemblies. Open the comparison page and filter oligomeric states

View Construct and Data Evidence
UniProt name RPOA_BACSU
Isoform —
PDB entities 2
Chains and sequence ranges Author chain B； PDBConstruct 5–74； UniProt 245–314

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.

SAXS scattering curve SAXS Profile

SAXS profile for 3ihq

P(r) Distance Distribution P(r) Distribution

P(r) distribution for 3ihq
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2. Structure Basics 2. Structure Basics

Entry ID entry_id3ihq
Deposition date deposition_date2009-07-30
Structure title titleCrystal Structure of Reduced C10S Spx in Complex with the Alpha C-terminal Domain of RNA Polymeras
Keywords keywords;transcription regulation, oxidative stress, Spx, RNA Polymerase, Cytoplasm, Disulfide bond, Redox-active center, Stress response, Transcription, DNA-directed RNA polymerase, Nucleotidyltransferase, Transferase, Transcription-Transferase COMPLEX ;; Transcription/Transferase
Experimental Method methodX-RAY DIFFRACTION
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3. SAXS Parameters (CRYSOL theoretical calculation) 3. SAXS Parameters (CRYSOL)

Radius of gyration Rg (Guinier) rg_guinier18.91 Å
Radius of gyration Rg (electron density) rg_electron17.92 Å
Forward intensity I(0) i08118470.00
Molecular weight molecular_weight20930.0 kDa
Excluded volume excluded_volume26282 ų
Envelope volume envelope_volume31104 ų
Hydration-shell volume shell_volume15153 ų
Envelope diameter envelope_diameter60.8 Å
Shell Rg shell_rg23.26 Å
Envelope Rg envelope_rg18.18 Å
Shape Rg shape_rg17.92 Å
Total Rg total_rg18.79 Å
Total atoms total_atoms1468
Residues n_residues182
Spherical-harmonic order n_harmonics20
q range q_range— – 0.5000 Å−1
Data points n_points101
Shell type shell_typedirectional
Solvent electron density solvent_density0.3340 e/ų
Shell contrast contrast_shell0.0300 e/ų
CRYSOL version crysol_version4.1.3
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4. P(r) Distance Distribution (GNOM inversion) 4. P(r) Analysis (GNOM)

Maximum dimension Dmax dmax61.5 Å
Rg (real space) rg_real18.90 Å
Rg uncertainty (real space) rg_real_error0.42 Å
I(0) (real space) i0_real8.1180e+06
I(0) uncertainty (real space) i0_real_error1.0730e+05
Rg (reciprocal space) rg_reciprocal18.90 Å
I(0) (reciprocal space) i0_reciprocal8118000.0000
Solution quality estimate total_estimate0.8866
Solution quality rating solution_quality GOOD a GOOD solution
P(r) peaks n_peaks2
Primary peak position r_peak_primary19.6 Å
Skewness Skewness skewness0.331
Kurtosis Kurtosis kurtosis-0.397
Angular range angular_range— – 0.4200 Å−1
Current regularization parameter α current_alpha0.0000
Highest regularization parameter α highest_alpha2814000.0000
Real-space data points n_real_points73
GNOM version gnom_version4.1.3
Quality Criteria quality_criteria AN1: 0.000; Oscil: 0.846; Stabil: 1.000; Sysdev: 1.000; Positv: 1.000; Valcen: 0.990; Smooth: 0.995
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5. Crystallography and Experiment 5. Crystallography & Experiment

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6. Entities and Polymers Entities & Polymers (4)

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7. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

Domain ID domain_idd3ihqa_
Class classc — Alpha and beta proteins (a/b)
Fold Fold foldc.47 — Thioredoxin fold
Superfamily Superfamily superfamilyc.47.1 — Thioredoxin-like
Family Family familyc.47.1.12 — ArsC-like
Domain ID domain_idd3ihqb_
Class classa — All alpha proteins
Fold Fold folda.60 — SAM domain-like
Superfamily Superfamily superfamilya.60.3 — C-terminal domain of RNA polymerase alpha subunit
Family Family familya.60.3.1 — C-terminal domain of RNA polymerase alpha subunit

CATH v4.4 (2 domains)

Domain ID domain_id3ihqA00
Class class3 — Alpha Beta
Architecture architecture40 — 3-Layer(aba) Sandwich
Topology topology30 — Glutaredoxin
Homologous superfamily homologous superfamily10 — Glutaredoxin
Domain ID domain_id3ihqB00
Class class1 — Mainly Alpha
Architecture architecture10 — Orthogonal Bundle
Topology topology150 — DNA polymerase; domain 1
Homologous superfamily homologous superfamily20 — 5' to 3' exonuclease, C-terminal subdomain
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8. Citations (2)

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9. Files and Curves (10)