[English] 日本語

- EMDB-1204: Three-dimensional structure of a type III glutamine synthetase by... -
+
Open data
-
Basic information
Entry | Database: EMDB / ID: EMD-1204 | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Title | Three-dimensional structure of a type III glutamine synthetase by single-particle reconstruction. | |||||||||
![]() | Glutamine synthetase type III from Bacteroides fragilis | |||||||||
![]() |
| |||||||||
Function / homology | Glutamine synthetase, N-terminal domain![]() | |||||||||
Biological species | ![]() | |||||||||
Method | single particle reconstruction / cryo EM / negative staining / Resolution: 15.0 Å | |||||||||
![]() | van Rooyen JM / Abratt VR / Sewell BT | |||||||||
![]() | ![]() Title: Three-dimensional structure of a type III glutamine synthetase by single-particle reconstruction. Authors: Jason M van Rooyen / Valerie R Abratt / B Trevor Sewell / ![]() Abstract: GlnN, the type III glutamine synthetase (GSIII) from the medically important, anaerobic, opportunistic pathogen Bacteroides fragilis, has 82.8 kDa subunits that share only 9% sequence identity with ...GlnN, the type III glutamine synthetase (GSIII) from the medically important, anaerobic, opportunistic pathogen Bacteroides fragilis, has 82.8 kDa subunits that share only 9% sequence identity with the type I glutamine synthetases (GSI), the only family for which a structure is known. Active GlnN was found predominantly in a single peak that eluted from a calibrated gel-filtration chromatography column at a position equaivalent to 0.86(+/-0.08) MDa. Negative-stain electron microscopy enabled the identification of double-ringed particles and single hexameric rings ("pinwheels") resulting from partial staining. A 2D average of these pinwheels showed marked similarity to the corresponding structures found in preparations of GSI, except that the arms of the subunits were 40% longer. Reconstructions from particles embedded in vitreous ice showed that GlnN has a double-ringed, dodecameric structure with a 6-fold dihedral space group (D6) symmetry and dimensions of 17.0 nm parallel with the 6-fold axis and 18.3 nm parallel with the 2-fold axes. The structures, combined with a sequence alignment based on structural principles, showed how many aspects of the structure of GSI, and most notably the alpha/beta barrel fold active site were preserved. There was evidence for the presence of this structure in the reconstructed volume, thus, identifying the indentations between the pinwheel spokes as putative active sites and suggesting conservation of the overall molecular geometry found in GSI despite their low level of global homology. Furthermore, docking of GSI into the reconstruction left sufficient plausibly located unoccupied density to account for the additional residues in GSIII, thus validating the structure. | |||||||||
History |
|
-
Structure visualization
Movie |
![]() |
---|---|
Structure viewer | EM map: ![]() ![]() ![]() |
Supplemental images |
-
Downloads & links
-EMDB archive
Map data | ![]() | 2.6 MB | ![]() | |
---|---|---|---|---|
Header (meta data) | ![]() ![]() | 9.9 KB 9.9 KB | Display Display | ![]() |
Images | ![]() | 17.5 KB | ||
Archive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
-
Links
EMDB pages | ![]() ![]() |
---|
-
Map
File | ![]() | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Annotation | Glutamine synthetase type III from Bacteroides fragilis | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 4 Å | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Density |
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
CCP4 map header:
|
-Supplemental data
-
Sample components
-Entire : B.fragilis GlnN purified from E.coli
Entire | Name: B.fragilis GlnN purified from E.coli |
---|---|
Components |
|
-Supramolecule #1000: B.fragilis GlnN purified from E.coli
Supramolecule | Name: B.fragilis GlnN purified from E.coli / type: sample / ID: 1000 / Oligomeric state: One dodecamer of GlnN / Number unique components: 1 |
---|---|
Molecular weight | Experimental: 1.3 MDa / Theoretical: 990 KDa / Method: Calibrated gel-filtration |
-Macromolecule #1: GlnN
Macromolecule | Name: GlnN / type: protein_or_peptide / ID: 1 / Name.synonym: GSIII Details: Recombinant GlnN purified from GlnA deficient E.coli mutant Number of copies: 12 / Oligomeric state: Dodecamer / Recombinant expression: Yes |
---|---|
Source (natural) | Organism: ![]() |
Molecular weight | Experimental: 990 KDa / Theoretical: 1.3 MDa |
Recombinant expression | Organism: ![]() ![]() |
Sequence | InterPro: Glutamine synthetase, N-terminal domain |
-Experimental details
-Structure determination
Method | negative staining, cryo EM |
---|---|
![]() | single particle reconstruction |
Aggregation state | particle |
-
Sample preparation
Concentration | 1 mg/mL |
---|---|
Buffer | pH: 7.15 / Details: 10 mM Imidazole-HCl, 10 mM MnCl2 |
Staining | Type: NEGATIVE / Details: cryo-EM |
Vitrification | Cryogen name: ETHANE / Chamber humidity: 90 % / Chamber temperature: 77 K / Instrument: HOMEMADE PLUNGER Details: Vitrification instrument: EMBL-designed plunger. Vitrification carried out in humidified room. Method: Blot for 2 seconds before |
-
Electron microscopy
Microscope | FEI TECNAI 20 |
---|---|
Temperature | Average: 77 K |
Date | Apr 26, 2004 |
Image recording | Category: FILM / Film or detector model: KODAK SO-163 FILM / Digitization - Scanner: OTHER / Digitization - Sampling interval: 14 µm / Number real images: 53 Details: Images were digitized using an Ilford Leafscan and downsized by a factor of 14 (as above) to give a sampling of 4 Å/pixel Bits/pixel: 16 |
Electron beam | Acceleration voltage: 200 kV / Electron source: ![]() |
Electron optics | Calibrated magnification: 50000 / Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2 mm / Nominal defocus max: 3.47 µm / Nominal defocus min: 1.01 µm / Nominal magnification: 50000 |
Sample stage | Specimen holder: Eucentric / Specimen holder model: GATAN LIQUID NITROGEN |
-
Image processing
CTF correction | Details: Phase flipping of particles in defocus groups |
---|---|
Final reconstruction | Applied symmetry - Point group: D6 (2x6 fold dihedral) / Algorithm: OTHER / Resolution.type: BY AUTHOR / Resolution: 15.0 Å / Resolution method: FSC 0.5 CUT-OFF / Software - Name: SPIDER / Number images used: 15688 |
Final two d classification | Number classes: 120 |
-Atomic model buiding 1
Software | Name: Situs |
---|---|
Details | Protocol: rigid body |
Refinement | Space: REAL / Protocol: RIGID BODY FIT / Target criteria: CC score |