6VWP

Crystal structure of E. coli guanosine kinase in complex with ppGpp

6VWP の概要

• エントリーDOI: 10.2210/pdb6vwp/pdb
• 分子名称: Inosine-guanosine kinase, GUANOSINE-5',3'-TETRAPHOSPHATE, GUANOSINE, ... (5 entities in total)
• 機能のキーワード: transferase
• 由来する生物種: Escherichia coli (strain K12)
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 400275.66

構造登録者

Wang, B.,Grant, R.A.,Laub, M.T. (登録日: 2020-02-20, 公開日: 2020-10-07, 最終更新日: 2023-10-11)

主引用文献

Wang, B.,Grant, R.A.,Laub, M.T.
ppGpp Coordinates Nucleotide and Amino-Acid Synthesis in E. coli During Starvation.
Mol.Cell, 80:29-, 2020

PubMed Abstract: (p)ppGpp is a nucleotide messenger universally produced in bacteria following nutrient starvation. In E. coli, ppGpp inhibits purine nucleotide synthesis by targeting several different enzymes, but the physiological significance of their inhibition is unknown. Here, we report the structural basis of inhibition for one target, Gsk, the inosine-guanosine kinase. Gsk creates an unprecedented, allosteric binding pocket for ppGpp by restructuring terminal sequences, which restrains conformational dynamics necessary for catalysis. Guided by this structure, we generated a chromosomal mutation that abolishes Gsk regulation by ppGpp. This mutant strain accumulates abnormally high levels of purine nucleotides following amino-acid starvation, compromising cellular fitness. We demonstrate that this unrestricted increase in purine nucleotides is detrimental because it severely depletes pRpp and essential, pRpp-derived metabolites, including UTP, histidine, and tryptophan. Thus, our results reveal the significance of ppGpp's regulation of purine nucleotide synthesis and a critical mechanism by which E. coli coordinates biosynthetic processes during starvation.

PubMed: 32857952
DOI: 10.1016/j.molcel.2020.08.005

実験手法

X-RAY DIFFRACTION (3.45 Å)