6U2T

Crystal structure of the T-state of maize C4-phosphoenolpyruvate carboxylase in complex with malate

6U2T の概要

• エントリーDOI: 10.2210/pdb6u2t/pdb
• 分子名称: Phosphoenolpyruvate carboxylase, D-MALATE, SULFATE ION, ... (5 entities in total)
• 機能のキーワード: c4 metabolism, allosteric regulation, r and t states, plant protein, lyase
• 由来する生物種: Zea mays (Maize)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 439621.20

構造登録者

Carrizosa-Carbajal, E.l.,Munoz-Clares, R.A.,Gonzalez-Segura, L. (登録日: 2019-08-20, 公開日: 2020-09-09, 最終更新日: 2024-09-11)

主引用文献

Carrizosa-Carbajal, E.I.,Gonzalez-Segura, L.,Munoz-Clares, R.A.
Two new T-state crystal structures of maize C 4 -phosphoenolpyruvate carboxylase reveal and suggest novel structural features of the allosteric regulation and carboxylation step.
Int.J.Biol.Macromol., :135134-135134, 2024

PubMed Abstract: To get a deeper understanding of the structural bases of the allosteric transition between T and R states of plant and bacterial phosphoenolpyruvate carboxylases (PEPCs), we obtained the first T-state crystal structures of the maize photosynthetic PEPC (ZmPEPC-C) and exhaustively compared them with the previously reported R-state ZmPEPC-C and other T-state structures. We identified previously unrecognized significant conformational changes in the T state: that of the α8-α9 loop, which connects the two kinds of activator allosteric sites with the active site, the conversion of the α30 helix into a 3 helix, leading to the disorganization of the active site lid and activators allosteric sites, and the closure of the inhibitor allosteric-site lid. Additionally, we identified previously overlooked, highly conserved residues of potential interest in the allosteric transition, including two histidines whose protonation might stabilize the T state. The crystal structures reported here also suggest similar tetrameric quaternary arrangements of PEPC enzymes in the R and T states, and the location of the bicarbonate binding site, as well as the conformational changes required for the carboxylation step. Our findings and working hypothesis advance the understanding of the structural features of the allosteric PEPC enzymes and provide a foundation for future experiments.

PubMed: 39208913
DOI: 10.1016/j.ijbiomac.2024.135134

実験手法

X-RAY DIFFRACTION (2.8 Å)