2BTM

DOES THE HIS12-LYS13 PAIR PLAY A ROLE IN THE ADAPTATION OF THERMOPHILIC TIMS TO HIGH TEMPERATURES?

2BTM の概要

• エントリーDOI: 10.2210/pdb2btm/pdb
• 分子名称: PROTEIN (TRIOSEPHOSPHATE ISOMERASE), 2-PHOSPHOGLYCOLIC ACID (3 entities in total)
• 機能のキーワード: thermophilic triose-phosphate, glycolysis, isomerase
• 由来する生物種: Geobacillus stearothermophilus
• 細胞内の位置: Cytoplasm (Probable): P00943
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 54275.34

構造登録者

Delboni, L.F.,Mande, S.C.,Hol, W.G.J. (登録日: 1999-01-04, 公開日: 1999-01-13, 最終更新日: 2025-11-12)

主引用文献

Alvarez, M.,Wouters, J.,Maes, D.,Mainfroid, V.,Rentier-Delrue, F.,Wyns, L.,Depiereux, E.,Martial, J.A.
Lys13 plays a crucial role in the functional adaptation of the thermophilic triose-phosphate isomerase from Bacillus stearothermophilus to high temperatures.
J.Biol.Chem., 274:19181-19187, 1999

PubMed Abstract: The thermophilic triose-phosphate isomerases (TIMs) of Bacillus stearothermophilus (bTIM) and Thermotoga maritima (tTIM) have been found to possess a His12-Lys13 pair instead of the Asn12-Gly13 pair normally present in mesophilic TIMs. His12 in bTIM was proposed to prevent deamidation at high temperature, while the precise role of Lys13 is unknown. To investigate the role of the His12 and Lys13 pair in the enzyme's thermoadaptation, we reintroduced the "mesophilic residues" Asn and Gly into both thermophilic TIMs. Neither double mutant displayed diminished structural stability, but the bTIM double mutant showed drastically reduced catalytic activity. No similar behavior was observed with the tTIM double mutant, suggesting that the presence of the His12 and Lys13 cannot be systematically correlated to thermoadaptation in TIMs. We determined the crystal structure of the bTIM double mutant complexed with 2-phosphoglycolate to 2.4-A resolution. A molecular dynamics simulation showed that upon substitution of Lys13 to Gly an increase of the flexibility of loop 1 is observed, causing an incorrect orientation of the catalytic Lys10. This suggests that Lys13 in bTIM plays a crucial role in the functional adaptation of this enzyme to high temperature. Analysis of bTIM single mutants supports this assumption.

PubMed: 10383424
DOI: 10.1074/jbc.274.27.19181

実験手法

X-RAY DIFFRACTION (2.4 Å)