2BE9

Crystal structure of the CTP-liganded (T-State) aspartate transcarbamoylase from the extremely thermophilic archaeon Sulfolobus acidocaldarius

2BE9 の概要

• エントリーDOI: 10.2210/pdb2be9/pdb
• 関連するPDBエントリー: 1PG5
• 分子名称: Aspartate carbamoyltransferase, Aspartate carbamoyltransferase regulatory chain, ZINC ION, ... (6 entities in total)
• 機能のキーワード: atcase, hyperthermophilic, temperature, transferase, allosteric, holoenzyme, ctp complex
• 由来する生物種: Sulfolobus acidocaldarius; 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 53822.29

構造登録者

De Vos, D.,Savvides, S.N.,Van Beeumen, J.J. (登録日: 2005-10-23, 公開日: 2006-10-31, 最終更新日: 2023-08-23)

主引用文献

De Vos, D.,Xu, Y.,Aerts, T.,Van Petegem, F.,Van Beeumen, J.J.
Crystal structure of Sulfolobus acidocaldarius aspartate carbamoyltransferase in complex with its allosteric activator CTP.
Biochem.Biophys.Res.Commun., 372:40-44, 2008

PubMed Abstract: Aspartate carbamoyltransferase (ATCase) is a paradigm for allosteric regulation of enzyme activity. B-class ATCases display very similar homotropic allosteric behaviour, but differ extensively in their heterotropic patterns. The ATCase from the thermoacidophilic archaeon Sulfolobus acidocaldarius, for example, is strongly activated by its metabolic pathway's end product CTP, in contrast with Escherichia coli ATCase which is inhibited by CTP. To investigate the structural basis of this property, we have solved the crystal structure of the S. acidocaldarius enzyme in complex with CTP. Structure comparison reveals that effector binding does not induce similar large-scale conformational changes as observed for the E. coli ATCase. However, shifts in sedimentation coefficients upon binding of the bi-substrate analogue PALA show the existence of structurally distinct allosteric states. This suggests that the so-called "Nucleotide-Perturbation model" for explaining heterotropic allosteric behaviour, which is based on global conformational strain, is not a general mechanism of B-class ATCases.

PubMed: 18477471
DOI: 10.1016/j.bbrc.2008.04.173

実験手法

X-RAY DIFFRACTION (2.6 Å)