2A0F

Structure of D236A mutant E. coli Aspartate Transcarbamoylase in presence of Phosphonoacetamide at 2.90 A resolution

2A0F の概要

• エントリーDOI: 10.2210/pdb2a0f/pdb
• 関連するPDBエントリー: 1D09 8AT1
• 分子名称: Aspartate carbamoyltransferase catalytic chain, Aspartate carbamoyltransferase regulatory chain, PHOSPHONOACETAMIDE, ... (5 entities in total)
• 機能のキーワード: homotropic cooperativity, catalytic cycle, allosteric regulation, alternate conformations, transferase-transferase regulator complex, transferase/transferase regulator
• 由来する生物種: Escherichia coli; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 103143.31

構造登録者

Stieglitz, K.A.,Dusinberre, K.J.,Cardia, J.P.,Tsuruta, H.,Kantrowitz, E.R. (登録日: 2005-06-16, 公開日: 2005-09-27, 最終更新日: 2023-08-23)

主引用文献

Stieglitz, K.A.,Dusinberre, K.J.,Cardia, J.P.,Tsuruta, H.,Kantrowitz, E.R.
Structure of the E.coli Aspartate Transcarbamoylase Trapped in the Middle of the Catalytic Cycle.
J.Mol.Biol., 352:478-486, 2005

PubMed Abstract: Snapshots of the catalytic cycle of the allosteric enzyme aspartate transcarbamoylase have been obtained via X-ray crystallography. The enzyme in the high-activity high-affinity R state contains two catalytic chains in the asymmetric unit that are different. The active site in one chain is empty, while the active site in the other chain contains an analog of the first substrate to bind in the ordered mechanism of the reaction. Small angle X-ray scattering shows that once the enzyme is converted to the R state, by substrate binding, the enzyme remains in the R state until substrates are exhausted. Thus, this structure represents the active form of the enzyme trapped at two different stages in the catalytic cycle, before the substrates bind (or after the products are released), and after the first substrate binds. Opening and closing of the catalytic chain domains explains how the catalytic cycle occurs while the enzyme remains globally in the R-quaternary structure.

PubMed: 16120448
DOI: 10.1016/j.jmb.2005.07.046

実験手法

X-RAY DIFFRACTION (2.9 Å)