1JI1

Crystal Structure Analysis of Thermoactinomyces vulgaris R-47 alpha-Amylase 1

1JI1 の概要

• エントリーDOI: 10.2210/pdb1ji1/pdb
• 関連するPDBエントリー: 1JI2
• 分子名称: ALPHA-AMYLASE I, CALCIUM ION (3 entities in total)
• 機能のキーワード: beta/alpha barrel, hydrolase
• 由来する生物種: Thermoactinomyces vulgaris
• 細胞内の位置: Secreted: Q60053
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 142461.06

構造登録者

Kamitori, S.,Abe, A.,Ohtaki, A.,Kaji, A.,Tonozuka, T.,Sakano, Y. (登録日: 2001-06-28, 公開日: 2002-06-05, 最終更新日: 2024-03-13)

主引用文献

Kamitori, S.,Abe, A.,Ohtaki, A.,Kaji, A.,Tonozuka, T.,Sakano, Y.
Crystal structures and structural comparison of Thermoactinomyces vulgaris R-47 alpha-amylase 1 (TVAI) at 1.6 A resolution and alpha-amylase 2 (TVAII) at 2.3 A resolution.
J.Mol.Biol., 318:443-453, 2002

PubMed Abstract: The X-ray crystal structures of Thermoactinomyces vulgaris R-47 alpha-amylase 1 (TVAI) and alpha-amylase 2 (TVAII) have been determined at 1.6 A and 2.3 A resolution, respectively. The structures of TVAI and TVAII have been refined, R-factor of 0.182 (R(free)=0.206) and 0.179 (0.224), respectively, with good chemical geometries. Both TVAI and TVAII have four domains, N, A, B and C, and all very similar in structure. However, there are some differences in the structures between them. Domain N of TVAI interacts strongly with domains A and B, giving a spherical shape structure to the enzyme, while domain N of TVAII is isolated from the other domains, which leads to the formation of a dimer. TVAI has three bound Ca ions, whereas TVAII has only one. TVAI has eight extra loops compared to TVAII, while TVAII has two extra loops compared to TVAI. TVAI can hydrolyze substrates more efficiently than TVAII with a high molecular mass such as starch, while TVAII is much more active against cyclodextrins than TVAI and other alpha-amylases. A structural comparison of the active sites has clearly revealed this difference in substrate specificity.

PubMed: 12051850
DOI: 10.1016/S0022-2836(02)00111-0

実験手法

X-RAY DIFFRACTION (1.6 Å)