Related Experiment Video
Updated: May 16, 2026

2 in 1: One-step Affinity Purification for the Parallel Analysis of Protein-Protein and Protein-Metabolite Complexes
Published on: August 6, 2018
Enzymatic and molecular characterization of Arabidopsis ppGpp pyrophosphohydrolase, AtNUDX26
Daisuke Ito1, Takahiro Kato, Takanori Maruta
1Department of Advanced Bioscience, Faculty of Agriculture, Kinki University, Nara, Japan.
Abstract:
Not only in bacteria but also in plant cells, guanosine-3',5'-tetraphosphate (ppGpp) is an important signaling molecule, that affects various cellular processes. In this study, we identified nucleoside diphosphates linked to some moiety X (Nudix) hydrolases, AtNUDX11, 15, 25, and 26, having ppGpp pyrophosphohydrolase activity from Arabidopsis plants. Among these, AtNUDX26 localized in chloroplasts had the highest Vmax and kcat values, leading to high catalytic efficiency, kcat/Km. The activity of AtNUDX26 required Mg2+ or Mn2+ ions as cofactor and was optimal at pH 9.0 and 50 °C. The expression of AtNUDX26 and of ppGpp metabolism-associated genes was regulated by various types of stress, suggesting that AtNUDX26 regulates cellular ppGpp levels in response to stress and impacts gene expression in chloroplasts. This is the first report on the molecular properties of ppGpp pyrophosphohydrolases in plants.

