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Open data
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Basic information
Entry | Database: PDB / ID: 7mh1 | ||||||
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Title | Human CTPS2 bound to CTP | ||||||
![]() | CTP synthase 2 | ||||||
![]() | LIGASE / glutaminase / amidoligase / nucleotide metabolism | ||||||
Function / homology | ![]() CTP synthase (glutamine hydrolysing) / CTP synthase activity / cytoophidium / pyrimidine nucleotide metabolic process / 'de novo' CTP biosynthetic process / pyrimidine nucleobase biosynthetic process / Interconversion of nucleotide di- and triphosphates / CTP biosynthetic process / glutamine metabolic process / ATP binding ...CTP synthase (glutamine hydrolysing) / CTP synthase activity / cytoophidium / pyrimidine nucleotide metabolic process / 'de novo' CTP biosynthetic process / pyrimidine nucleobase biosynthetic process / Interconversion of nucleotide di- and triphosphates / CTP biosynthetic process / glutamine metabolic process / ATP binding / identical protein binding / cytoplasm / cytosol Similarity search - Function | ||||||
Biological species | ![]() | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.8 Å | ||||||
![]() | Lynch, E.M. / Kollman, J.M. | ||||||
Funding support | ![]()
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![]() | ![]() Title: Structural basis for isoform-specific inhibition of human CTPS1. Authors: Eric M Lynch / Michael A DiMattia / Steven Albanese / Gydo C P van Zundert / Jesse M Hansen / Joel D Quispe / Madison A Kennedy / Andreas Verras / Kenneth Borrelli / Angela V Toms / Neelu ...Authors: Eric M Lynch / Michael A DiMattia / Steven Albanese / Gydo C P van Zundert / Jesse M Hansen / Joel D Quispe / Madison A Kennedy / Andreas Verras / Kenneth Borrelli / Angela V Toms / Neelu Kaila / Kevin D Kreutter / Joshua J McElwee / Justin M Kollman / ![]() Abstract: Cytidine triphosphate synthase 1 (CTPS1) is necessary for an effective immune response, as revealed by severe immunodeficiency in CTPS1-deficient individuals [E. Martin ], [] [510], [288-292] ([2014]) ...Cytidine triphosphate synthase 1 (CTPS1) is necessary for an effective immune response, as revealed by severe immunodeficiency in CTPS1-deficient individuals [E. Martin ], [] [510], [288-292] ([2014]). CTPS1 expression is up-regulated in activated lymphocytes to expand CTP pools [E. Martin ], [] [510], [288-292] ([2014]), satisfying increased demand for nucleic acid and lipid synthesis [L. D. Fairbanks, M. Bofill, K. Ruckemann, H. A. Simmonds], [ ] [270], [29682-29689] ([1995]). Demand for CTP in other tissues is met by the CTPS2 isoform and nucleoside salvage pathways [E. Martin ], [] [510], [288-292] ([2014]). Selective inhibition of the proliferative CTPS1 isoform is therefore desirable in the treatment of immune disorders and lymphocyte cancers, but little is known about differences in regulation of the isoforms or mechanisms of known inhibitors. We show that CTP regulates both isoforms by binding in two sites that clash with substrates. CTPS1 is less sensitive to CTP feedback inhibition, consistent with its role in increasing CTP levels in proliferation. We also characterize recently reported small-molecule inhibitors, both CTPS1 selective and nonselective. Cryo-electron microscopy (cryo-EM) structures reveal these inhibitors mimic CTP binding in one inhibitory site, where a single amino acid substitution explains selectivity for CTPS1. The inhibitors bind to CTPS assembled into large-scale filaments, which for CTPS1 normally represents a hyperactive form of the enzyme [E. M. Lynch ], [] [24], [507-514] ([2017]). This highlights the utility of cryo-EM in drug discovery, particularly for cases in which targets form large multimeric assemblies not amenable to structure determination by other techniques. Both inhibitors also inhibit the proliferation of human primary T cells. The mechanisms of selective inhibition of CTPS1 lay the foundation for the design of immunosuppressive therapies. | ||||||
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 | ![]() | 728.8 KB | Display | ![]() |
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PDB format | ![]() | 616.4 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
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-Related structure data
Related structure data | ![]() 23833MC ![]() 7mgzC ![]() 7mh0C ![]() 7mifC ![]() 7migC ![]() 7mihC ![]() 7miiC ![]() 7mipC ![]() 7miuC ![]() 7mivC M: map data used to model this data C: citing same article ( |
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Similar structure data |
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Links
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Assembly
Deposited unit | ![]()
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1 |
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Components
#1: Protein | Mass: 65759.430 Da / Num. of mol.: 4 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() ![]() References: UniProt: Q9NRF8, CTP synthase (glutamine hydrolysing) #2: Chemical | ChemComp-CTP / #3: Chemical | ChemComp-MG / Has ligand of interest | N | |
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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: CTPS2 tetramer / Type: COMPLEX / Entity ID: #1 / Source: RECOMBINANT |
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Source (natural) | Organism: ![]() |
Source (recombinant) | Organism: ![]() ![]() |
Buffer solution | pH: 7.9 |
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: 90 e/Å2 / Detector mode: SUPER-RESOLUTION / Film or detector model: GATAN K2 SUMMIT (4k x 4k) |
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Processing
EM software |
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
3D reconstruction | Resolution: 2.8 Å / Resolution method: FSC 0.5 CUT-OFF / Num. of particles: 46236 / Symmetry type: POINT |