{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,10]],"date-time":"2026-10-10T05:40:12Z","timestamp":1791610812156,"version":"4.3.4"},"reference-count":50,"publisher":"National Academy of Sciences","issue":"42","license":[{"start":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T00:00:00Z","timestamp":1791504000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002855","name":"Ministry of Science and Technology of the People\u2019s Republic of China","doi-asserted-by":"publisher","award":["2021YFA0804700"],"award-info":[{"award-number":["2021YFA0804700"]}],"id":[{"id":"10.13039\/501100002855","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"MOST | National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["32370744; 32350710195"],"award-info":[{"award-number":["32370744; 32350710195"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000265","name":"UKRI | Medical Research Council","doi-asserted-by":"publisher","award":["MC_UU_12021\/3; MC_U137788471"],"award-info":[{"award-number":["MC_UU_12021\/3; MC_U137788471"]}],"id":[{"id":"10.13039\/501100000265","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[2026,10,20]]},"abstract":"<jats:p>\n                    Cytidine triphosphate (CTP), a fundamental building block of RNA, plays vital roles in diverse biological processes. CTP synthase (CTPS) is the only known enzyme for de novo synthesis of CTP. Efficient CTPS catalysis requires guanosine triphosphate (GTP) in a dose-dependent, nonconsumptive manner; however, the precise mechanism by which GTP drives CTP formation remains unclear. Here, we integrate a series of cryo-EM structures of\n                    <jats:italic toggle=\"yes\">Drosophila melanogaster<\/jats:italic>\n                    CTPS captured from actively catalyzing samples with biochemical and mutagenesis analyses, yielding 34 distinct CTPS states at resolutions up to 2.0 \u00c5. We find that GTP binds to and dissociates from CTPS once per catalytic cycle, thereby enabling the production of a single CTP molecule. Initial GTP engagement requires formation of 4-phosphoryl-UTP in the AL domain, whereas full stabilization of GTP binding is promoted by occupancy of the GAT active site. Together, these two checkpoints couple GTP recruitment and stabilization to catalytic progress in the two domains, enabling the coordinated synthesis of one CTP molecule per GTP binding\u2013dissociation cycle. Moreover, the GTP-recognition site is highly conserved across the three domains of life. These findings establish a comprehensive mechanistic framework for efficient CTPS catalysis and define \u201ceffector-cycling\u201d\u2014in which GTP undergoes obligatory binding and dissociation during each catalytic cycle to regulate an intermediate step in a multistep catalytic process\u2014as a distinct mode of allosteric regulation.\n                  <\/jats:p>","DOI":"10.1073\/pnas.2620272123","type":"journal-article","created":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T16:32:35Z","timestamp":1791563555000},"update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":1,"title":["GTP orchestrates CTP synthase via an allosteric effector\u2013cycling mechanism"],"prefix":"10.1073","volume":"123","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5342-4761","authenticated-orcid":false,"given":"Chen-Jun","family":"Guo","sequence":"first","affiliation":[{"id":[{"id":"https:\/\/ror.org\/030bhh786","id-type":"ROR","asserted-by":"publisher"}],"name":"School of Life Science and Technology, ShanghaiTech University","place":["Shanghai, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-5071-9707","authenticated-orcid":false,"given":"Yu-Fen","family":"Wu","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/030bhh786","id-type":"ROR","asserted-by":"publisher"}],"name":"School of Life Science and Technology, ShanghaiTech University","place":["Shanghai, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-2751-535X","authenticated-orcid":false,"given":"Shu-Ying","family":"Guo","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/030bhh786","id-type":"ROR","asserted-by":"publisher"}],"name":"School of Life Science and Technology, ShanghaiTech University","place":["Shanghai, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jia-Li","family":"Lu","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/030bhh786","id-type":"ROR","asserted-by":"publisher"}],"name":"School of Life Science and Technology, ShanghaiTech University","place":["Shanghai, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Liang","family":"Xu","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/030bhh786","id-type":"ROR","asserted-by":"publisher"}],"name":"School of Life Science and Technology, ShanghaiTech University","place":["Shanghai, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2444-7985","authenticated-orcid":false,"given":"You","family":"Fu","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/030bhh786","id-type":"ROR","asserted-by":"publisher"}],"name":"School of Life Science and Technology, ShanghaiTech University","place":["Shanghai, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0000-2415","authenticated-orcid":false,"given":"Xian","family":"Zhou","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/030bhh786","id-type":"ROR","asserted-by":"publisher"}],"name":"School of Life Science and Technology, ShanghaiTech University","place":["Shanghai, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5873-0450","authenticated-orcid":false,"given":"Jiale","family":"Zhong","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/030bhh786","id-type":"ROR","asserted-by":"publisher"}],"name":"School of Life Science and Technology, ShanghaiTech University","place":["Shanghai, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-9263-5095","authenticated-orcid":false,"given":"Zherong","family":"Zhang","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/030bhh786","id-type":"ROR","asserted-by":"publisher"}],"name":"School of Life Science and Technology, ShanghaiTech University","place":["Shanghai, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4834-8554","authenticated-orcid":false,"given":"Ji-Long","family":"Liu","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/030bhh786","id-type":"ROR","asserted-by":"publisher"}],"name":"School of Life Science and Technology, ShanghaiTech University","place":["Shanghai, China"]},{"id":[{"id":"https:\/\/ror.org\/052gg0110","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Physiology, Anatomy and Genetics, University of Oxford","place":["Oxford, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[2026,10,9]]},"reference":[{"key":"e_1_3_4_1_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi00752a015"},{"key":"e_1_3_4_2_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41556-022-00965-1"},{"key":"e_1_3_4_3_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.plipres.2008.03.004"},{"key":"e_1_3_4_4_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41589-024-01689-z"},{"key":"e_1_3_4_5_2","doi-asserted-by":"publisher","DOI":"10.1038\/nature13386"},{"key":"e_1_3_4_6_2","doi-asserted-by":"publisher","DOI":"10.1158\/0008-5472.CAN-21-1707"},{"key":"e_1_3_4_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0065-3527(08)60082-2"},{"key":"e_1_3_4_8_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.111139498"},{"key":"e_1_3_4_9_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.chembiol.2015.05.016"},{"key":"e_1_3_4_10_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.2107968118"},{"key":"e_1_3_4_11_2","doi-asserted-by":"publisher","DOI":"10.1038\/271071a0"},{"key":"e_1_3_4_12_2","doi-asserted-by":"publisher","DOI":"10.3390\/biom12050647"},{"key":"e_1_3_4_13_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.immuni.2024.11.020"},{"key":"e_1_3_4_14_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41586-025-08835-0"},{"key":"e_1_3_4_15_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.169.7.3023-3028.1987"},{"key":"e_1_3_4_16_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi0496945"},{"key":"e_1_3_4_17_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0021-9258(18)95692-9"},{"key":"e_1_3_4_18_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi00794a008"},{"key":"e_1_3_4_19_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0021-9258(18)99515-3"},{"key":"e_1_3_4_20_2","doi-asserted-by":"publisher","DOI":"10.1016\/S1570-9639(04)00066-4"},{"key":"e_1_3_4_21_2","doi-asserted-by":"publisher","DOI":"10.1046\/j.1432-1033.2002.03175.x"},{"key":"e_1_3_4_22_2","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M707803200"},{"key":"e_1_3_4_23_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.2026621118"},{"key":"e_1_3_4_24_2","unstructured":"C.-J. Guo Reaction-based cryo-EM resolves the continuous conformational spectrum of CTP synthase catalysis. Proc. Natl. Acad. Sci. U.S.A. 123 e2620271123 (2026)."},{"key":"e_1_3_4_25_2","doi-asserted-by":"publisher","DOI":"10.1042\/bj20021110"},{"key":"e_1_3_4_26_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1742-4658.2004.04525.x"},{"key":"e_1_3_4_27_2","doi-asserted-by":"publisher","DOI":"10.1002\/mlf2.12119"},{"key":"e_1_3_4_28_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jmb.2024.168750"},{"key":"e_1_3_4_29_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.bbagen.2018.08.008"},{"key":"e_1_3_4_30_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0076-6879(85)13039-9"},{"key":"e_1_3_4_31_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.tibs.2008.05.009"},{"key":"e_1_3_4_32_2","doi-asserted-by":"crossref","unstructured":"H. N. Motlagh J. O. Wrabl J. Li V. J. Hilser The ensemble nature of allostery. Nature 508 331\u2013339 (2014).","DOI":"10.1038\/nature13001"},{"key":"e_1_3_4_33_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase DON-condition. Protein Data Bank. https:\/\/www.rcsb.org\/structure\/9UAR. Deposited 1 April 2025.","DOI":"10.2210\/pdb9uar\/pdb"},{"key":"e_1_3_4_34_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase dDON-condition state 1. Protein Data Bank. https:\/\/www.rcsb.org\/structure\/9V2B. Deposited 19 May 2025.","DOI":"10.2210\/pdb9uar\/pdb"},{"key":"e_1_3_4_35_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase dDON-condition state 2. Protein Data Bank. https:\/\/www.rcsb.org\/structure\/9V2C. Deposited 19 May 2025.","DOI":"10.2210\/pdb9uar\/pdb"},{"key":"e_1_3_4_36_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase dDON-condition state 3. Protein Data Bank. https:\/\/www.rcsb.org\/structure\/9V2D. Deposited 19 May 2025.","DOI":"10.2210\/pdb9uar\/pdb"},{"key":"e_1_3_4_37_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase dDON-condition state 4. Protein Data Bank. https:\/\/www.rcsb.org\/structure\/9V2E. Deposited 19 May 2025.","DOI":"10.2210\/pdb9uar\/pdb"},{"key":"e_1_3_4_38_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase dDON-condition state 5. Protein Data Bank. https:\/\/www.rcsb.org\/structure\/9V2F. Deposited 19 May 2025.","DOI":"10.2210\/pdb9uar\/pdb"},{"key":"e_1_3_4_39_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase dDON-condition state 6. Protein Data Bank. https:\/\/www.rcsb.org\/structure\/9V2G. Deposited 19 May 2025.","DOI":"10.2210\/pdb9uar\/pdb"},{"key":"e_1_3_4_40_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase dDON-condition state 7. Protein Data Bank. https:\/\/www.rcsb.org\/structure\/9V2H. Deposited 19 May 2025.","DOI":"10.2210\/pdb9uar\/pdb"},{"key":"e_1_3_4_41_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase dDON-condition state 8. Protein Data Bank. https:\/\/www.rcsb.org\/structure\/9V2I. Deposited 19 May 2025.","DOI":"10.2210\/pdb9uar\/pdb"},{"key":"e_1_3_4_42_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase DON-condition. Electron Microscopy Data Bank. https:\/\/www.ebi.ac.uk\/emdb\/EMD-63990. Deposited 1 April 2025.","DOI":"10.2210\/pdb9uar\/pdb"},{"key":"e_1_3_4_43_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase dDON-condition state 1. Electron Microscopy Data Bank. https:\/\/www.ebi.ac.uk\/emdb\/EMD-64723. Deposited 19 May 2025.","DOI":"10.2210\/pdb9uar\/pdb"},{"key":"e_1_3_4_44_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase dDON-condition state 2. Electron Microscopy Data Bank. https:\/\/www.ebi.ac.uk\/emdb\/EMD-64724. Deposited 19 May 2025.","DOI":"10.2210\/pdb9uar\/pdb"},{"key":"e_1_3_4_45_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase dDON-condition state 3. Electron Microscopy Data Bank. https:\/\/www.ebi.ac.uk\/emdb\/EMD-64725. Deposited 19 May 2025.","DOI":"10.2210\/pdb9uar\/pdb"},{"key":"e_1_3_4_46_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase dDON-condition state 4. Electron Microscopy Data Bank. https:\/\/www.ebi.ac.uk\/emdb\/EMD-64726. Deposited 19 May 2025.","DOI":"10.2210\/pdb9uar\/pdb"},{"key":"e_1_3_4_47_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase dDON-condition state 5. Electron Microscopy Data Bank. https:\/\/www.ebi.ac.uk\/emdb\/EMD-64727. Deposited 19 May 2025.","DOI":"10.2210\/pdb9uar\/pdb"},{"key":"e_1_3_4_48_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase dDON-condition state 6. Electron Microscopy Data Bank. https:\/\/www.ebi.ac.uk\/emdb\/EMD-64728. Deposited 19 May 2025.","DOI":"10.2210\/pdb9uar\/pdb"},{"key":"e_1_3_4_49_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase dDON-condition state 7. Electron Microscopy Data Bank. https:\/\/www.ebi.ac.uk\/emdb\/EMD-64729. Deposited 19 May 2025.","DOI":"10.2210\/pdb9uar\/pdb"},{"key":"e_1_3_4_50_2","doi-asserted-by":"crossref","unstructured":"C. J. Guo CTP synthase dDON-condition state 8. Electron Microscopy Data Bank. https:\/\/www.ebi.ac.uk\/emdb\/EMD-64730. Deposited 19 May 2025.","DOI":"10.2210\/pdb9uar\/pdb"}],"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.2620272123","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T16:32:44Z","timestamp":1791563564000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/10.1073\/pnas.2620272123"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10,9]]},"references-count":50,"journal-issue":{"issue":"42","published-print":{"date-parts":[[2026,10,20]]}},"alternative-id":["10.1073\/pnas.2620272123"],"URL":"https:\/\/doi.org\/10.1073\/pnas.2620272123","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10,9]]},"assertion":[{"value":"2026-06-15","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-09-09","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-10-09","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e2620272123"}}