4EWN

Structure of HisF-D130V+D176V with bound rCdRP

4EWN の概要

• エントリーDOI: 10.2210/pdb4ewn/pdb
• 分子名称: Imidazole glycerol phosphate synthase subunit HisF, 1-(O-carboxy-phenylamino)-1-deoxy-D-ribulose-5-phosphate (3 entities in total)
• 機能のキーワード: lyase
• 由来する生物種: Thermotoga maritima
• 細胞内の位置: Cytoplasm: Q9X0C6
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 28073.20

構造登録者

Reisinger, B.,Bocola, M.,Rajendran, C.,List, F.,Sterner, R. (登録日: 2012-04-27, 公開日: 2012-12-05, 最終更新日: 2024-02-28)

主引用文献

Reisinger, B.,Bocola, M.,List, F.,Claren, J.,Rajendran, C.,Sterner, R.
A sugar isomerization reaction established on various (beta-alpha)8-barrel scaffolds is based on substrate-assisted catalysis
Protein Eng.Des.Sel., 25:751-760, 2012

PubMed Abstract: In the course of tryptophan biosynthesis, the isomerization of phosphoribosylanthranilate (PRA) is catalyzed by the (βα)₈-barrel enzyme TrpF. The reaction occurs via a general acid-base mechanism with an aspartate and a cysteine residue acting as acid and base, respectively. PRA isomerase activity could be established on two (βα)₈-barrel enzymes involved in histidine biosynthesis, namely HisA and HisF, and on a HisAF chimera, by introducing two aspartate-to-valine substitutions. We have analyzed the reaction mechanism underlying this engineered activity by measuring its pH dependence, solving the crystal structure of a HisF variant with bound product analogue, and applying molecular dynamics simulations and mixed quantum and molecular mechanics calculations. The results suggest that PRA is anchored by the C-terminal phosphate-binding sites of HisA, HisF and HisAF. As a consequence, a conserved aspartate residue, which is equivalent to Cys7 from TrpF, is properly positioned to act as catalytic base. However, no obvious catalytic acid corresponding to Asp126 from TrpF could be identified in the three proteins. Instead, this role appears to be carried out by the carboxylate group of the anthranilate moiety of PRA. Thus, the engineered PRA isomerization activity is based on a reaction mechanism including substrate-assisted catalysis and thus differs substantially from the naturally evolved reaction mechanism used by TrpF.

PubMed: 23109729
DOI: 10.1093/protein/gzs080

実験手法

X-RAY DIFFRACTION (1.903 Å)