5E4R

Crystal structure of domain-duplicated synthetic class II ketol-acid reductoisomerase 2Ia_KARI-DD

5E4R の概要

• エントリーDOI: 10.2210/pdb5e4r/pdb
• 分子名称: Ketol-acid reductoisomerase, NADP NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE, MAGNESIUM ION, ... (7 entities in total)
• 機能のキーワード: ketol-acid reductiosomerase, protein knot, psuedodimer, protein engineering, chimera protein, oxidoreductase
• 由来する生物種: Ignisphaera aggregans (strain DSM 17230 / JCM 13409 / AQ1.S1); 詳細
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 56339.24

構造登録者

Cahn, J.K.B.,Brinkmann-Chen, S.,Buller, A.R.,Arnold, F.H. (登録日: 2015-10-07, 公開日: 2015-12-23, 最終更新日: 2023-09-27)

主引用文献

Cahn, J.K.,Brinkmann-Chen, S.,Buller, A.R.,Arnold, F.H.
Artificial domain duplication replicates evolutionary history of ketol-acid reductoisomerases.
Protein Sci., 25:1241-1248, 2016

PubMed Abstract: The duplication of protein structural domains has been proposed as a common mechanism for the generation of new protein folds. A particularly interesting case is the class II ketol-acid reductoisomerase (KARI), which putatively arose from an ancestral class I KARI by duplication of the C-terminal domain and corresponding loss of obligate dimerization. As a result, the class II enzymes acquired a deeply embedded figure-of-eight knot. To test this evolutionary hypothesis we constructed a novel class II KARI by duplicating the C-terminal domain of a hyperthermostable class I KARI. The new protein is monomeric, as confirmed by gel filtration and X-ray crystallography, and has the deeply knotted class II KARI fold. Surprisingly, its catalytic activity is nearly unchanged from the parent KARI. This provides strong evidence in support of domain duplication as the mechanism for the evolution of the class II KARI fold and demonstrates the ability of domain duplication to generate topological novelty in a function-neutral manner.

PubMed: 26644020
DOI: 10.1002/pro.2852

実験手法

X-RAY DIFFRACTION (1.94 Å)