1CH0

RNASE T1 VARIANT WITH ALTERED GUANINE BINDING SEGMENT

1CH0 の概要

• エントリーDOI: 10.2210/pdb1ch0/pdb
• 分子名称: PROTEIN (RIBONUCLEASE T1), CALCIUM ION, GUANOSINE-2'-MONOPHOSPHATE, ... (5 entities in total)
• 機能のキーワード: ribonuclease, hydrolase
• 由来する生物種: Aspergillus oryzae
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 34353.52

構造登録者

Hoeschler, K.,Hoier, H.,Orth, P.,Hubner, B.,Saenger, W.,Hahn, U. (登録日: 1999-03-30, 公開日: 1999-12-22, 最終更新日: 2024-11-13)

主引用文献

Hoschler, K.,Hoier, H.,Hubner, B.,Saenger, W.,Orth, P.,Hahn, U.
Structural analysis of an RNase T1 variant with an altered guanine binding segment.
J.Mol.Biol., 294:1231-1238, 1999

PubMed Abstract: The ribonuclease T1 variant 9/5 with a guanine recognition segment, altered from the wild-type amino acid sequence 41-KYNNYE-46 to 41-EFRNWQ-46, has been cocrystallised with the specific inhibitor 2'-GMP. The crystal structure has been refined to a crystallographic R factor of 0.198 at 2.3 A resolution. Despite a size reduction of the binding pocket, pushing the inhibitor outside by 1 A, 2'-GMP is fixed to the primary recognition site due to increased aromatic stacking interactions. The phosphate group of 2'-GMP is located about 4.2 A apart from its position in wild-type ribonuclease T1-2'-GMP complexes, allowing a Ca(2+), coordinating this phosphate group, to enter the binding pocket. The crystallographic data can be aligned with the kinetic characterisation of the variant, showing a reduction of both, guanine affinity and turnover rate. The presence of Ca(2+) was shown to inhibit variant 9/5 and wild-type enzyme to nearly the same extent.

PubMed: 10600381
DOI: 10.1006/jmbi.1999.3324

実験手法

X-RAY DIFFRACTION (2.3 Å)