1B5P

THERMUS THERMOPHILUS ASPARTATE AMINOTRANSFERASE DOUBLE MUTANT 1

1B5P の概要

• エントリーDOI: 10.2210/pdb1b5p/pdb
• 分子名称: PROTEIN (ASPARTATE AMINOTRANSFERASE), PHOSPHATE ION, PYRIDOXAL-5'-PHOSPHATE, ... (4 entities in total)
• 機能のキーワード: aminotransferase, pyridoxal enzyme, transferase
• 由来する生物種: Thermus thermophilus
• 細胞内の位置: Cytoplasm (By similarity): Q56232
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 84946.12

構造登録者

Ura, H.,Nakai, T.,Kawaguchi, S.I.,Miyahara, I.,Hirotsu, K.,Kuramitsu, S. (登録日: 1999-01-07, 公開日: 2003-09-02, 最終更新日: 2023-08-09)

主引用文献

Ura, H.,Nakai, T.,Kawaguchi, S.I.,Miyahara, I.,Hirotsu, K.,Kuramitsu, S.
Substrate recognition mechanism of thermophilic dual-substrate enzyme
J.BIOCHEM.(TOKYO), 130:89-98, 2001

PubMed Abstract: Aspartate aminotransferase from an extremely thermophilic bacterium, Thermus thermophilus HB8 (ttAspAT), has been believed to be specific for an acidic substrate. However, stepwise introduction of mutations in the active-site residues finally changed its substrate specificity to that of a dual-substrate enzyme. The final mutant, [S15D, T17V, K109S, S292R] ttAspAT, is active toward both acidic and hydrophobic substrates. During the course of stepwise mutation, the activities toward acidic and hydrophobic substrates changed independently. The introduction of a mobile Arg292* residue into ttAspAT was the key step in the change to a "dual-substrate" enzyme. The substrate recognition mechanism of this thermostable "dual-substrate" enzyme was confirmed by X-ray crystallography. This work together with previous studies on various enzymes suggest that this unique "dual-substrate recognition" mechanism is a feature of not only aminotransferases but also other enzymes.

PubMed: 11432784

実験手法

X-RAY DIFFRACTION (1.8 Å)