4Q0V

Crystal structure of Acinetobacter sp. DL28 L-ribose isomerase mutant E204Q in complex with L-ribulose

4Q0V の概要

• エントリーDOI: 10.2210/pdb4q0v/pdb
• 関連するPDBエントリー: 4Q0P 4Q0Q 4Q0S 4Q0U
• 分子名称: L-Ribose isomerase, COBALT (II) ION, L-ribulose, ... (6 entities in total)
• 機能のキーワード: cupin barrel, isomerase, sugar binding
• 由来する生物種: Acinetobacter
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 30021.23

構造登録者

Yoshida, H.,Yoshihara, A.,Teraoka, M.,Izumori, K.,Kamitori, S. (登録日: 2014-04-02, 公開日: 2014-05-28, 最終更新日: 2023-11-08)

主引用文献

Yoshida, H.,Yoshihara, A.,Teraoka, M.,Terami, Y.,Takata, G.,Izumori, K.,Kamitori, S.
X-ray structure of a novel L-ribose isomerase acting on a non-natural sugar L-ribose as its ideal substrate.
Febs J., 281:3150-3164, 2014

PubMed Abstract: l-Ribose, a pentose, is not known to exist in nature. Although organisms typically do not have a metabolic pathway that uses l-ribose as a carbon source, prokaryotes use various sugars as carbon sources for survival. Acinetobacter sp. DL-28 has been shown to express the novel enzyme, l-ribose isomerase (AcL-RbI), which catalyzes reversible isomerization between l-ribose and l-ribulose. AcL-RbI showed the highest activity to l-ribose, followed by d-lyxose with 47% activity, and had no significant amino acid sequence similarity to structure-known proteins, except for weak homology with the d-lyxose isomerases from Escherichia coli O157 : H7 (18%) and Bacillus subtilis strain (19%). Thus, AcL-RbI is expected to have the unique three-dimensional structure to recognize l-ribose as its ideal substrate. The X-ray structures of AcL-RbI in complexes with substrates were determined. AcL-RbI had a cupin-type β-barrel structure, and the catalytic site was found between two large β-sheets with a bound metal ion. The catalytic site structures clearly showed that AcL-RbI adopted a cis-enediol intermediate mechanism for the isomerization reaction using two glutamate residues (Glu113 and Glu204) as acid/base catalysts. In its crystal form, AcL-RbI formed a unique homotetramer with many substrate sub-binding sites, which likely facilitated capture of the substrate.

PubMed: 24846739
DOI: 10.1111/febs.12850

実験手法

X-RAY DIFFRACTION (1.98 Å)