EMD-23817

Single-particle
2.42 Å
EMD-23817 Deposition: 10/04/2021
Map released: 05/01/2022
Last modified: 25/12/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-23817

Glutamate synthase, glutamate dehydrogenase counter-enzyme complex

EMD-23817

Single-particle
2.42 Å
EMD-23817 Deposition: 10/04/2021
Map released: 05/01/2022
Last modified: 25/12/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Bacillus subtilis
Sample: GudB6-GltA2-GltB2
Fitted models: 7mfm (Avg. Q-score: 0.558)

Deposition Authors: Jayaraman V , Lee DJ
A counter-enzyme complex regulates glutamate metabolism in Bacillus subtilis.
Jayaraman V , Lee DJ, Elad N, Vimer S , Sharon M , Fraser JS , Tawfik DS
(2022) Nat Chem Biol , 18 , 161 - 170
PUBMED: 34931064
DOI: doi:10.1038/s41589-021-00919-y
ISSN: 1552-4469
Abstract:
Multi-enzyme assemblies composed of metabolic enzymes catalyzing sequential reactions are being increasingly studied. Here, we report the discovery of a 1.6 megadalton multi-enzyme complex from Bacillus subtilis composed of two enzymes catalyzing opposite ('counter-enzymes') rather than sequential reactions: glutamate synthase (GltAB) and glutamate dehydrogenase (GudB), which make and break glutamate, respectively. In vivo and in vitro studies show that the primary role of complex formation is to inhibit the activity of GudB. Using cryo-electron microscopy, we elucidated the structure of the complex and the molecular basis of inhibition of GudB by GltAB. The complex exhibits unusual oscillatory progress curves and is necessary for both planktonic growth, in glutamate-limiting conditions, and for biofilm growth, in glutamate-rich media. The regulation of a key metabolic enzyme by complexing with its counter enzyme may thus enable cell growth under fluctuating glutamate concentrations.