6XY9

Crystal structure of haloalkane dehalogenase DbeA-M1 loop variant from Bradyrhizobium elkanii

6XY9 の概要

• エントリーDOI: 10.2210/pdb6xy9/pdb
• 分子名称: Haloalkane dehalogenase, CHLORIDE ION, ACETATE ION, ... (4 entities in total)
• 機能のキーワード: haloalakane dehalogenase, microbial hydrolase, loop-helix engineering, hydrolase
• 由来する生物種: Bradyrhizobium elkanii USDA 94
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 67722.38

構造登録者

Prudnikova, T.,Rezacova, P.,Kuta Smatanova, I.,Chaloupkova, R.,Damborsky, J. (登録日: 2020-01-29, 公開日: 2020-07-22, 最終更新日: 2024-01-24)

主引用文献

Marek, M.,Chaloupkova, R.,Prudnikova, T.,Sato, Y.,Rezacova, P.,Nagata, Y.,Kuta Smatanova, I.,Damborsky, J.
Structural and catalytic effects of surface loop-helix transplantation within haloalkane dehalogenase family.
Comput Struct Biotechnol J, 18:1352-1362, 2020

PubMed Abstract: Engineering enzyme catalytic properties is important for basic research as well as for biotechnological applications. We have previously shown that the reshaping of enzyme access tunnels via the deletion of a short surface loop element may yield a haloalkane dehalogenase variant with markedly modified substrate specificity and enantioselectivity. Here, we conversely probed the effects of surface loop-helix transplantation from one enzyme to another within the enzyme family of haloalkane dehalogenases. Precisely, we transplanted a nine-residue long extension of L9 loop and α4 helix from DbjA into the corresponding site of DbeA. Biophysical characterization showed that this fragment transplantation did not affect the overall protein fold or oligomeric state, but lowered protein stability (Δ  = -5 to 6 °C). Interestingly, the crystal structure of DbeA mutant revealed the unique structural features of enzyme access tunnels, which are known determinants of catalytic properties for this enzyme family. Biochemical data confirmed that insertion increased activity of DbeA with various halogenated substrates and altered its enantioselectivity with several linear β-bromoalkanes. Our findings support a protein engineering strategy employing surface loop-helix transplantation for construction of novel protein catalysts with modified catalytic properties.

PubMed: 32612758
DOI: 10.1016/j.csbj.2020.05.019

実験手法

X-RAY DIFFRACTION (2.2 Å)