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Open data
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Basic information
Entry | Database: PDB / ID: 7rfg | ||||||||||||
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Title | HUMAN IMPDH1 TREATED WITH GTP, IMP, AND NAD+ OCTAMER-CENTERED | ||||||||||||
![]() | Isoform 5 of Inosine-5'-monophosphate dehydrogenase 1 | ||||||||||||
![]() | OXIDOREDUCTASE / METABOLISM / FILAMENT / ALLOSTERY / ADENINE | ||||||||||||
Function / homology | ![]() Purine ribonucleoside monophosphate biosynthesis / IMP dehydrogenase activity / IMP dehydrogenase / GMP biosynthetic process / Azathioprine ADME / GTP biosynthetic process / azurophil granule lumen / secretory granule lumen / ficolin-1-rich granule lumen / Potential therapeutics for SARS ...Purine ribonucleoside monophosphate biosynthesis / IMP dehydrogenase activity / IMP dehydrogenase / GMP biosynthetic process / Azathioprine ADME / GTP biosynthetic process / azurophil granule lumen / secretory granule lumen / ficolin-1-rich granule lumen / Potential therapeutics for SARS / nucleic acid binding / nucleotide binding / Neutrophil degranulation / DNA binding / RNA binding / extracellular region / identical protein binding / nucleus / metal ion binding / cytosol / cytoplasm Similarity search - Function | ||||||||||||
Biological species | ![]() | ||||||||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.6 Å | ||||||||||||
Model details | FILAMENT ASSEMBLY INTERFACE RECONSTRUCTION | ||||||||||||
![]() | Burrell, A.L. / Kollman, J.M. | ||||||||||||
Funding support | ![]()
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![]() | ![]() Title: IMPDH1 retinal variants control filament architecture to tune allosteric regulation. Authors: Anika L Burrell / Chuankai Nie / Meerit Said / Jacqueline C Simonet / David Fernández-Justel / Matthew C Johnson / Joel Quispe / Rubén M Buey / Jeffrey R Peterson / Justin M Kollman / ![]() ![]() Abstract: Inosine-5'-monophosphate dehydrogenase (IMPDH), a key regulatory enzyme in purine nucleotide biosynthesis, dynamically assembles filaments in response to changes in metabolic demand. Humans have two ...Inosine-5'-monophosphate dehydrogenase (IMPDH), a key regulatory enzyme in purine nucleotide biosynthesis, dynamically assembles filaments in response to changes in metabolic demand. Humans have two isoforms: IMPDH2 filaments reduce sensitivity to feedback inhibition, while IMPDH1 assembly remains uncharacterized. IMPDH1 plays a unique role in retinal metabolism, and point mutants cause blindness. Here, in a series of cryogenic-electron microscopy structures we show that human IMPDH1 assembles polymorphic filaments with different assembly interfaces in extended and compressed states. Retina-specific splice variants introduce structural elements that reduce sensitivity to GTP inhibition, including stabilization of the extended filament form. Finally, we show that IMPDH1 disease mutations fall into two classes: one disrupts GTP regulation and the other has no effect on GTP regulation or filament assembly. These findings provide a foundation for understanding the role of IMPDH1 in retinal function and disease and demonstrate the diverse mechanisms by which metabolic enzyme filaments are allosterically regulated. | ||||||||||||
History |
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Structure visualization
Movie |
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Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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Download
PDBx/mmCIF format | ![]() | 1.2 MB | Display | ![]() |
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PDB format | ![]() | 1 MB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
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-Related structure data
Related structure data | ![]() 24441MC ![]() 7rerC ![]() 7resC ![]() 7rfeC ![]() 7rffC ![]() 7rfhC ![]() 7rfiC ![]() 7rgdC ![]() 7rgiC ![]() 7rglC ![]() 7rgmC ![]() 7rgqC C: citing same article ( M: map data used to model this data |
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Similar structure data |
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Links
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Assembly
Deposited unit | ![]()
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Components
#1: Protein | Mass: 55470.652 Da / Num. of mol.: 8 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() ![]() #2: Chemical | ChemComp-GTP / #3: Chemical | ChemComp-ATP / #4: Chemical | ChemComp-IMP / Has ligand of interest | Y | |
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-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: FILAMENT / 3D reconstruction method: single particle reconstruction |
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Sample preparation
Component | Name: Assembly interface of IMPDH1 filament bound to ATP, IMP, NAD+ Type: COMPLEX / Entity ID: #1 / Source: RECOMBINANT |
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Molecular weight | Value: 55405 MDa / Experimental value: NO |
Source (natural) | Organism: ![]() |
Source (recombinant) | Organism: ![]() ![]() |
Buffer solution | pH: 7 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Vitrification | Cryogen name: ETHANE |
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Electron microscopy imaging
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Microscopy | Model: FEI TITAN KRIOS |
Electron gun | Electron source: ![]() |
Electron lens | Mode: BRIGHT FIELD |
Image recording | Electron dose: 50 e/Å2 / Film or detector model: GATAN K2 SUMMIT (4k x 4k) |
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Processing
CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION |
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3D reconstruction | Resolution: 2.6 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 42500 / Symmetry type: POINT |