7RNR

Yeast CTP Synthase (Ura8) Bundle Bound to Substrates at Low pH

This is a non-PDB format compatible entry.

Summary for 7RNR

• Entry DOI: 10.2210/pdb7rnr/pdb
• EMDB information: 24581
• Descriptor: CTP synthase, ADENOSINE-5'-TRIPHOSPHATE, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: glutaminase and amido-ligase, protein fibril
• Biological source: Saccharomyces cerevisiae (Baker's yeast)
• Total number of polymer chains: 20
• Total formula weight: 1269582.00

Authors

Hansen, J.M.,Lynch, E.M.,Farrell, D.P.,DiMaio, F.,Quispe, J.,Kollman, J.M. (deposition date: 2021-07-29, release date: 2021-11-24, Last modification date: 2024-06-05)

Primary citation

Hansen, J.M.,Horowitz, A.,Lynch, E.M.,Farrell, D.P.,Quispe, J.,DiMaio, F.,Kollman, J.M.
Cryo-EM structures of CTP synthase filaments reveal mechanism of pH-sensitive assembly during budding yeast starvation.
Elife, 10:-, 2021

PubMed Abstract: Many metabolic enzymes self-assemble into micron-scale filaments to organize and regulate metabolism. The appearance of these assemblies often coincides with large metabolic changes as in development, cancer, and stress. Yeast undergo cytoplasmic acidification upon starvation, triggering the assembly of many metabolic enzymes into filaments. However, it is unclear how these filaments assemble at the molecular level and what their role is in the yeast starvation response. CTP Synthase (CTPS) assembles into metabolic filaments across many species. Here, we characterize in vitro polymerization and investigate in vivo consequences of CTPS assembly in yeast. Cryo-EM structures reveal a pH-sensitive assembly mechanism and highly ordered filament bundles that stabilize an inactive state of the enzyme, features unique to yeast CTPS. Disruption of filaments in cells with non-assembly or pH-insensitive mutations decreases growth rate, reflecting the importance of regulated CTPS filament assembly in homeotstasis.

PubMed: 34734801
DOI: 10.7554/eLife.73368

Experimental method

ELECTRON MICROSCOPY (3.3 Å)