Metagenome-derived Haloalkane Dehalogenases with Novel Catalytic Properties


Kotik, M., Vanacek, P., Kunka, A., Prokop, Z., Damborsky, J.




Haloalkane dehalogenases (HLDs) are environmentally relevant enzymes cleaving a carbon-halogen bond in a wide range of halogenated pollutants. PCR with degenerate primers and genome-walking was used for the retrieval of four HLD-encoding genes from groundwater-derived environmental DNA. Using specific primers and the environmental DNA as a template, we succeeded in generating additional amplicons, resulting altogether in three clusters of sequences with each cluster comprising 8–13 closely related putative HLD-encoding genes. A phylogenetic analysis of the translated genes revealed that three HLDs are members of the HLD-I subfamily, whereas one gene encodes an enzyme from the subfamily HLD-II. Two metagenome-derived HLDs, eHLD-B and eHLD-C, each from a different subfamily, were heterologously produced in active form, purified and characterized in terms of their thermostability, pH and temperature optimum, quaternary structure, substrate specificity towards thirty halogenated compounds, and enantioselectivity. eHLD-B and eHLD-C showed striking differences in their activities, substrate preferences and their tolerance to temperature. Profound differences were also determined in the enantiopreference and enantioselectivity of these enzymes towards selected substrates. Comparing our data with those of known HLDs revealed that eHLD-C exhibits a unique combination of high thermostability, high activity and an unusually broad pH optimum, which covers the entire range of pH 5.5–8.9. Moreover, a so far unreported high thermostability for HLDs was determined for this enzyme at pH values lower than 6.0. Thus eHLD-C represents an attractive and novel biocatalyst for biotechnological applications.

Full text


Kotik, M., Vanacek, P., Kunka, A., Prokop, Z., Damborsky, J., 2017: Metagenome-derived Haloalkane Dehalogenases with Novel Catalytic Properties. Applied Microbiology and Biotechnology 101: 6385-6397.

Ondrej Vavra celebrating success with his presentation on CaverDock
Lecture by Dr. Stavrakis from ETH Zurich
High evaluation of the team’s research performance
Klaudia Chmelova and Veronika Liskova passed doctoral state exam
ELIXIR CZ annual conference 15 – 16 Nov, 2017
New video explaining the goals of Rafts4Biotech EU project
Invitation to a presentation by Synthetic Genomics