The Tetrameric Structure of a Novel Haloalkane Dehalogenase DpaA from Paraglaciecola agarilytica NO2
Mazur, A., Prudnikova, T., Grinkevich, P., Mesters, J. R., Mrazova, D., Chaloupkova, R., Damborsky, J., Kuty, M., Kolenko, P., Kuta Smatanova, I.
ACTA CRYSTALLOGRAPHICA SECTION D77: 347-356 (2021)
Haloalkane dehalogenases (EC 126.96.36.199) are microbial enzymes that catalyse the hydrolytic conversion of halogenated compounds resulting in halide ion, proton and alcohol. These enzymes are used in industrial biocatalysis, bioremediation, and biosensing of environmental pollutants or for molecular tagging in cell biology. The novel haloalkane dehalogenase DpaA described herein was isolated from the psychrophilic and halophilic bacteria Paraglaciecola agarilytica NO2, which was found in marine sediment collected from the East Sea near Korea. The gel filtration experiments and size exclusion chromatography provided information about dimeric composition of the enzyme in the solution. The DpaA enzyme was crystallized using the sitting drop vapour diffusion method, yielding rod-like crystals that diffracted X-rays to 2.0 Å resolution. Diffraction data analysis unveiled a case of merohedral twinning and subsequent structure modeling and refinement resulted in a tetrameric model of DpaA, highlighting an uncommon multimeric nature for a protein belonging to the HLD-I subfamily.