[English] 日本語
![](img/lk-miru.gif)
- PDB-7q56: Single Particle Cryo-EM structure of photosynthetic A8B8 glyceral... -
+
Open data
-
Basic information
Entry | Database: PDB / ID: 7q56 | ||||||
---|---|---|---|---|---|---|---|
Title | Single Particle Cryo-EM structure of photosynthetic A8B8 glyceraldehyde-3-phosphate dehydrogenase (minor conformer) from Spinacia oleracea. | ||||||
![]() |
| ||||||
![]() | ![]() ![]() ![]() | ||||||
Function / homology | ![]() ![]() ![]() ![]() ![]() ![]() Similarity search - Function | ||||||
Biological species | ![]() ![]() | ||||||
Method | ![]() ![]() ![]() | ||||||
![]() | Marotta, R. / Fermani, S. / Sparla, F. / Trost, P. / Del Giudice, A. | ||||||
Funding support | ![]()
| ||||||
![]() | ![]() Title: Unravelling the regulation pathway of photosynthetic AB-GAPDH. Authors: Roberto Marotta / Alessandra Del Giudice / Libero Gurrieri / Silvia Fanti / Paolo Swuec / Luciano Galantini / Giuseppe Falini / Paolo Trost / Simona Fermani / Francesca Sparla / ![]() Abstract: Oxygenic phototrophs perform carbon fixation through the Calvin-Benson cycle. Different mechanisms adjust the cycle and the light-harvesting reactions to rapid environmental changes. Photosynthetic ...Oxygenic phototrophs perform carbon fixation through the Calvin-Benson cycle. Different mechanisms adjust the cycle and the light-harvesting reactions to rapid environmental changes. Photosynthetic glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is a key enzyme in the cycle. In land plants, different photosynthetic GAPDHs exist: the most abundant isoform is formed by AB heterotetramers and the least abundant by A homotetramers. Regardless of the subunit composition, GAPDH is the major consumer of photosynthetic NADPH and its activity is strictly regulated. While A-GAPDH is regulated by CP12, AB-GAPDH is autonomously regulated through the C-terminal extension (CTE) of its B subunits. Reversible inhibition of AB-GAPDH occurs via the oxidation of a cysteine pair located in the CTE and the substitution of NADP(H) with NAD(H) in the cofactor-binding site. These combined conditions lead to a change in the oligomerization state and enzyme inhibition. SEC-SAXS and single-particle cryo-EM analysis were applied to reveal the structural basis of this regulatory mechanism. Both approaches revealed that spinach (AB)-GAPDH oligomers with n = 1, 2, 4 and 5 co-exist in a dynamic system. B subunits mediate the contacts between adjacent tetramers in AB and AB oligomers. The CTE of each B subunit penetrates into the active site of a B subunit of the adjacent tetramer, which in turn moves its CTE in the opposite direction, effectively preventing the binding of the substrate 1,3-bisphosphoglycerate in the B subunits. The whole mechanism is made possible, and eventually controlled, by pyridine nucleotides. In fact, NAD(H), by removing NADP(H) from A subunits, allows the entrance of the CTE into the active site of the B subunit, hence stabilizing inhibited oligomers. | ||||||
History |
|
-
Structure visualization
Structure viewer | Molecule: ![]() ![]() |
---|
-
Downloads & links
-
Download
PDBx/mmCIF format | ![]() | 955.6 KB | Display | ![]() |
---|---|---|---|---|
PDB format | ![]() | 807.3 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
---|
-Related structure data
Related structure data | ![]() 13827MC ![]() 7q53C ![]() 7q54C ![]() 7q55C ![]() 7q57C M: map data used to model this data C: citing same article ( |
---|---|
Similar structure data | Similarity search - Function & homology ![]() |
-
Links
-
Assembly
Deposited unit | ![]()
|
---|---|
1 |
|
-
Components
#1: Protein | Mass: 39403.957 Da / Num. of mol.: 8 / Source method: isolated from a natural source / Source: (natural) ![]() ![]() #2: Protein | Mass: 36256.391 Da / Num. of mol.: 8 / Source method: isolated from a natural source / Source: (natural) ![]() ![]() #3: Chemical | ChemComp-NAD / ![]() Has ligand of interest | Y | |
---|
-Experimental details
-Experiment
Experiment | Method: ![]() |
---|---|
EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: ![]() |
-
Sample preparation
Component | Name: A8B8 glyceraldehyde-3-phospahte dehydrogenase hetero-hexdecamer (minor conformer)complexed with NAD. Type: COMPLEX / Entity ID: #1-#2 / Source: NATURAL |
---|---|
Source (natural) | Organism: ![]() ![]() |
Buffer solution | pH: 7.4 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied![]() ![]() |
Specimen support | Grid material: COPPER / Grid mesh size: 400 divisions/in. / Grid type: C-flat-1.2/1.3 |
Vitrification![]() | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE |
-
Electron microscopy imaging
Experimental equipment | ![]() Model: Tecnai Polara / Image courtesy: FEI Company |
---|---|
Microscopy | Model: FEI POLARA 300 |
Electron gun | Electron source![]() ![]() |
Electron lens | Mode: BRIGHT FIELD![]() |
Image recording | Electron dose: 42 e/Å2 / Detector mode: COUNTING / Film or detector model: GATAN K2 SUMMIT (4k x 4k) |
-
Processing
Software | Name: PHENIX / Version: 1.17.1_3660: / Classification: refinement | ||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
CTF correction![]() | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
Symmetry | Point symmetry![]() ![]() | ||||||||||||||||||||||||
3D reconstruction![]() | Resolution: 7.1 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 10768 / Symmetry type: POINT | ||||||||||||||||||||||||
Atomic model building | PDB-ID: 2PKQ | ||||||||||||||||||||||||
Refine LS restraints |
|