3VND

Crystal structure of tryptophan synthase alpha-subunit from the psychrophile Shewanella frigidimarina K14-2

3VND の概要

• エントリーDOI: 10.2210/pdb3vnd/pdb
• 関連するPDBエントリー: 1V7Y
• 分子名称: Tryptophan synthase alpha chain, SULFATE ION, 3,6,9,12,15,18,21-HEPTAOXATRICOSANE-1,23-DIOL, ... (4 entities in total)
• 機能のキーワード: psychrophilic enzyme, cold adaptation, tryptophan synthase, lyase
• 由来する生物種: Shewanella frigidimarina
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 225839.42

構造登録者

Mitsuya, D.,Tanaka, S.,Matsumura, H.,Takano, K.,Urano, N.,Ishida, M. (登録日: 2012-01-12, 公開日: 2013-01-16, 最終更新日: 2023-11-08)

主引用文献

Mitsuya, D.,Tanaka, S.,Matsumura, H.,Urano, N.,Takano, K.,Ogasahara, K.,Takehira, M.,Yutani, K.,Ishida, M.
Strategy for cold adaptation of the tryptophan synthase alpha subunit from the psychrophile Shewanella frigidimarina K14-2: crystal structure and physicochemical properties
J.Biochem., 155:73-82, 2014

PubMed Abstract: To investigate the molecular basis of cold adaptation of enzymes, we determined the crystal structure of the tryptophan synthase α subunit (SfTSA) from the psychrophile Shewanella frigidimarina K14-2 by X-ray analysis at 2.6-Å resolution and also examined its physicochemical properties. SfTSA was found to have the following characteristics: (i) The stabilities against heat and denaturant of SfTSA were lower than those of an α subunit (EcTSA) from Escherichia coli. This lower equilibrium stability originated from both a faster unfolding rate and a slower refolding rate; (ii) the heat denaturation of SfTSA was completely reversible at pH 7.0 and the solubility of denatured SfTSA was higher than that of denatured EcTSA. The two-state transition of denaturation for SfTSA was highly cooperative, whereas the denaturation process of EcTSA was considerably more complex and (iii) the global structure of SfTSA was quite similar to those of α subunits from other species. Relative to those other proteins, SfTSA exhibited an increase in cavity volume and a decrease in the number of ion pairs. SfTSA also lacks a hydrogen bond near loop B, related to catalytic function. These characteristics of SfTSA might provide the conformational flexibility required for catalytic activity at low temperatures.

PubMed: 24163283
DOI: 10.1093/jb/mvt098

実験手法

X-RAY DIFFRACTION (2.6 Å)