Biochemical Characteristics of the Novel Haloalkane Dehalogenase DatA, Isolated from the Plant Pathogen Agrobacterium tumefaciens C58

Abstract

We report the biochemical characterization of a novel haloalkane dehalogenase, DatA, isolated from the plant pathogen Agrobacterium tumefaciens C58. DatA possesses a peculiar pair of halide-stabilizing residues, Asn-Tyr, which have not been reported to play this role in other known haloalkane dehalogenases. DatA has a number of other unique characteristics, including substrate-dependent and cooperative kinetics, a dimeric structure, and excellent enantioselectivity toward racemic mixtures of chiral brominated alkanes and esters.

Biochemical Characterization of a Novel Haloalkane Dehalogenase from a Cold-Adapted Bacterium

“…The maximal activity of DpcA was detected at pH 8.7, which was similar to findings with other HLDs (15,(18)(19)(20)(21)26). The protein loses all activity below pH 6.4 and above pH 9.6.…”

“…This property is unique and has not been observed for any other HLD so far. The highest activities of other related enzymes lay in the temperature interval between 40 and 50°C (15,(18)(19)(20)(21)26). Another important finding is that the DpcA enzyme retained almost 27% of its maximal activity at 5°C.…”

“…DpcA was determined to be a monomer under tested conditions. The most biochemically characterized HLDs occur as monomers (8,15,21,26); some of them are dimers or form large oligomeric complexes (8,15,20).…”

Structure and activity of DmmA, a marine haloalkane dehalogenase

“…Among HLDs of known structure, only DbjA is dimeric in solution. 36 The helix a10 is central to the subunit contacts in both DmmA and DbjA, but the interfaces otherwise differ (Supporting Information Fig. 3).…”

<i>In-silico</i> Rational Protein Engineering and Design Approach to Improve Thermostability of a Haloalkane Dehalogenase Enzyme

“…Along with their potential applications in bioremediation, these enzymes have gained a limited interest in the industry for the production of optically pure alcohols. Therefore, the identification of novel dehalogenating enzymes is very much important in terms of their industrial utility Hasan et al, 2011). The catalytic reaction mechanism of the haloalkane dehalogenase enzymes (EC 3.8.1.5) involves the conversion of 1-haloalkane to a primary alcohol and halide ions following a hydrolysis reaction (Wackett, 1994;Prokop et al, 2003).…”