2D3C

Crystal Structure of the Maize Glutamine Synthetase complexed with ADP and Phosphinothricin Phosphate

Summary for 2D3C

• Entry DOI: 10.2210/pdb2d3c/pdb
• Related: 2D3A 2D3B
• Descriptor: glutamine synthetase, MANGANESE (II) ION, (2S)-2-AMINO-4-[METHYL(PHOSPHONOOXY)PHOSPHORYL]BUTANOIC ACID, ... (5 entities in total)
• Functional Keywords: glutamine synthetase maize herbicide, ligase
• Biological source: Zea mays
• Cellular location: Cytoplasm: P38561
• Total number of polymer chains: 10
• Total formula weight: 401171.61

Authors

Unno, H.,Uchida, T.,Sugawara, H.,Kurisu, G.,Sugiyama, T.,Yamaya, T.,Sakakibara, H.,Hase, T.,Kusunoki, M. (deposition date: 2005-09-26, release date: 2006-07-18, Last modification date: 2024-12-25)

Primary citation

Unno, H.,Uchida, T.,Sugawara, H.,Kurisu, G.,Sugiyama, T.,Yamaya, T.,Sakakibara, H.,Hase, T.,Kusunoki, M.
Atomic Structure of Plant Glutamine Synthetase: A KEY ENZYME FOR PLANT PRODUCTIVITY
J.Biol.Chem., 281:29287-29296, 2006

PubMed Abstract: Plants provide nourishment for animals and other heterotrophs as the sole primary producer in the food chain. Glutamine synthetase (GS), one of the essential enzymes for plant autotrophy catalyzes the incorporation of ammonia into glutamate to generate glutamine with concomitant hydrolysis of ATP, and plays a crucial role in the assimilation and re-assimilation of ammonia derived from a wide variety of metabolic processes during plant growth and development. Elucidation of the atomic structure of higher plant GS is important to understand its detailed reaction mechanism and to obtain further insight into plant productivity and agronomical utility. Here we report the first crystal structures of maize (Zea mays L.) GS. The structure reveals a unique decameric structure that differs significantly from the bacterial GS structure. Higher plants have several isoenzymes of GS differing in heat stability and catalytic properties for efficient responses to variation in the environment and nutrition. A key residue responsible for the heat stability was found to be Ile-161 in GS1a. The three structures in complex with substrate analogues, including phosphinothricin, a widely used herbicide, lead us to propose a mechanism for the transfer of phosphate from ATP to glutamate and to interpret the inhibitory action of phosphinothricin as a guide for the development of new potential herbicides.

PubMed: 16829528
DOI: 10.1074/jbc.M601497200

Experimental method

X-RAY DIFFRACTION (3.81 Å)