6XY9
Crystal structure of haloalkane dehalogenase DbeA-M1 loop variant from Bradyrhizobium elkanii
Summary for 6XY9
| Entry DOI | 10.2210/pdb6xy9/pdb |
| Descriptor | Haloalkane dehalogenase, CHLORIDE ION, ACETATE ION, ... (4 entities in total) |
| Functional Keywords | haloalakane dehalogenase, microbial hydrolase, loop-helix engineering, hydrolase |
| Biological source | Bradyrhizobium elkanii USDA 94 |
| Total number of polymer chains | 2 |
| Total formula weight | 67722.38 |
| Authors | Prudnikova, T.,Rezacova, P.,Kuta Smatanova, I.,Chaloupkova, R.,Damborsky, J. (deposition date: 2020-01-29, release date: 2020-07-22, Last modification date: 2024-01-24) |
| Primary citation | 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 Cited by 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: 32612758DOI: 10.1016/j.csbj.2020.05.019 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.2 Å) |
Structure validation
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