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Large-scale filament formation inhibits the activity of CTP synthetase.

Barry RM, Bitbol AF, Lorestani A, Charles EJ, Habrian CH, Hansen JM, Li HJ, Baldwin EP, Wingreen NS, Kollman JM, Gitai Z - Elife (2014)

Bottom Line: Structure-guided mutagenesis and mathematical modeling further indicate that coupling activity to polymerization promotes cooperative catalytic regulation.This previously uncharacterized regulatory mechanism is important for cellular function since a mutant that disrupts CtpS polymerization disrupts E. coli growth and metabolic regulation without reducing CTP levels.We propose that regulation by large-scale polymerization enables ultrasensitive control of enzymatic activity while storing an enzyme subpopulation in a conformationally restricted form that is readily activatable.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biology, Princeton University, Princeton, United States.

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CtpS higher order structures disassemble over time after centrifugation.Light scattering values from the pellet fraction of polymerized CtpS decrease over time after centrifugation from a baseline initial value. Pellet fraction stored on ice and compared to initial light scattering value immediately after resuspension.DOI:http://dx.doi.org/10.7554/eLife.03638.008
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fig1s5: CtpS higher order structures disassemble over time after centrifugation.Light scattering values from the pellet fraction of polymerized CtpS decrease over time after centrifugation from a baseline initial value. Pellet fraction stored on ice and compared to initial light scattering value immediately after resuspension.DOI:http://dx.doi.org/10.7554/eLife.03638.008

Mentions: We have performed the requested control and reach the same conclusions. The new data and text (clarifying that the “substrates” added were UTP and ATP) are presented in Figure 1–figure supplement 5 and discussed in the Results section.


Large-scale filament formation inhibits the activity of CTP synthetase.

Barry RM, Bitbol AF, Lorestani A, Charles EJ, Habrian CH, Hansen JM, Li HJ, Baldwin EP, Wingreen NS, Kollman JM, Gitai Z - Elife (2014)

CtpS higher order structures disassemble over time after centrifugation.Light scattering values from the pellet fraction of polymerized CtpS decrease over time after centrifugation from a baseline initial value. Pellet fraction stored on ice and compared to initial light scattering value immediately after resuspension.DOI:http://dx.doi.org/10.7554/eLife.03638.008
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4126345&req=5

fig1s5: CtpS higher order structures disassemble over time after centrifugation.Light scattering values from the pellet fraction of polymerized CtpS decrease over time after centrifugation from a baseline initial value. Pellet fraction stored on ice and compared to initial light scattering value immediately after resuspension.DOI:http://dx.doi.org/10.7554/eLife.03638.008
Mentions: We have performed the requested control and reach the same conclusions. The new data and text (clarifying that the “substrates” added were UTP and ATP) are presented in Figure 1–figure supplement 5 and discussed in the Results section.

Bottom Line: Structure-guided mutagenesis and mathematical modeling further indicate that coupling activity to polymerization promotes cooperative catalytic regulation.This previously uncharacterized regulatory mechanism is important for cellular function since a mutant that disrupts CtpS polymerization disrupts E. coli growth and metabolic regulation without reducing CTP levels.We propose that regulation by large-scale polymerization enables ultrasensitive control of enzymatic activity while storing an enzyme subpopulation in a conformationally restricted form that is readily activatable.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biology, Princeton University, Princeton, United States.

Show MeSH