1I4N

CRYSTAL STRUCTURE OF INDOLEGLYCEROL PHOSPHATE SYNTHASE FROM THERMOTOGA MARITIMA

1I4N の概要

• エントリーDOI: 10.2210/pdb1i4n/pdb
• 関連するPDBエントリー: 1igs 1juk 1jul 1pii
• 分子名称: INDOLE-3-GLYCEROL PHOSPHATE SYNTHASE, SULFATE ION (3 entities in total)
• 機能のキーワード: indoleglycerol phosphate synthase; thermotoga maritima; thermostable tim-barrel protein; salt bridges; electrostatic interactions, lyase
• 由来する生物種: Thermotoga maritima
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 57334.13

構造登録者

Knoechel, T.,Pappenberger, A.,Jansonius, J.N.,Kirschner, K. (登録日: 2001-02-22, 公開日: 2002-03-20, 最終更新日: 2024-11-20)

主引用文献

Knochel, T.,Pappenberger, A.,Jansonius, J.N.,Kirschner, K.
The crystal structure of indoleglycerol-phosphate synthase from Thermotoga maritima. Kinetic stabilization by salt bridges.
J.Biol.Chem., 277:8626-8634, 2002

PubMed Abstract: The crystal structure of the thermostable indoleglycerol-phosphate synthase from Thermotoga maritima (tIGPS) was determined at 2.5 A resolution. It was compared with the structures of the thermostable sIGPS from Sulfolobus solfataricus and of the thermolabile eIGPS from Escherichia coli. The main chains of the three (beta alpha)(8)-barrel proteins superimpose closely, and the packing of side chains in the beta-barrel cores, as well as the architecture of surface loops, is very similar. Both thermostable proteins have, however, 17 strong salt bridges, compared with only 10 in eIGPS. The number of additional salt bridges in tIGPS and sIGPS correlates well with their reduced rate of irreversible thermal inactivation at 90 degrees C. Only 3 of 17 salt bridges in tIGPS and sIGPS are topologically conserved. The major difference between the two proteins is the preference for interhelical salt bridges in sIGPS and intrahelical ones in tIGPS. The different implementation of salt bridges in the closely related proteins suggests that the stabilizing effect of salt bridges depends rather on the sum of their individual contributions than on their location. This observation is consistent with a protein unfolding mechanism where the simultaneous breakdown of all salt bridges is the rate-determining step.

PubMed: 11741953
DOI: 10.1074/jbc.M109517200

実験手法

X-RAY DIFFRACTION (2.5 Å)