9V1S
CTP synthase RXN-condition state 7
Summary for 9V1S
| Entry DOI | 10.2210/pdb9v1s/pdb |
| EMDB information | 64704 |
| Descriptor | CTP synthase, MAGNESIUM ION, ADENOSINE-5'-DIPHOSPHATE, ... (5 entities in total) |
| Functional Keywords | ctp synthase, ctps, ligase |
| Biological source | Drosophila melanogaster (fruit fly) |
| Total number of polymer chains | 3 |
| Total formula weight | 188919.39 |
| Authors | |
| Primary citation | Guo, C.J.,Wu, Y.F.,Guo, S.Y.,Fu, Y.,Wang, W.,Liu, J.L. Reaction-based cryo-EM resolves the continuous conformational spectrum of CTP synthase catalysis. Proc.Natl.Acad.Sci.USA, 123:e2620271123-e2620271123, 2026 Cited by PubMed Abstract: Capturing enzymes under native turnover conditions remains a grand challenge in structural biology. Here, we develop a reaction-based cryo-electron microscopy (cryo-EM) strategy that directly samples cytidine triphosphate synthase (CTPS) from actively catalyzing mixtures containing only natural substrates and allosteric effectors. By integrating reaction-based sampling with three-dimensional variability analysis, we resolve a continuous conformational spectrum of CTPS during catalysis. This approach visualizes the chemical progression of 4-phosphoryl-uridine triphosphate (4Pi-UTP) formation and reveals a previously unobserved co-occupancy pattern of adenosine triphosphate (ATP) and CTP at the reaction end point. Cross-validation with nonhydrolyzable ATP analogs demonstrates that UTP phosphorylation by ATP, rather than mere ATP binding, shifts the conformational ensemble toward more closed states. Our findings establish reaction-based cryo-EM as a framework for resolving chemically annotated conformational ensembles without predefining a single trapped intermediate. PubMed: 42853686DOI: 10.1073/pnas.2620271123 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3 Å) |
Structure validation
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