A haloalkane dehalogenase, DpcA, from Psychrobacter cryohalolentis K5, representing a novel psychrophilic member of the haloalkane dehalogenase family, was identified and biochemically characterized. DpcA exhibited a unique temperature profile with exceptionally high activities at low temperatures. The psychrophilic properties of DpcA make this enzyme promising for various environmental applications.

• MeSH
• Bacterial Proteins chemistry   genetics   metabolism   MeSH
• Adaptation, Physiological * MeSH
• Hydrolases chemistry   genetics   metabolism   MeSH
• Kinetics MeSH
• Hydrogen-Ion Concentration MeSH
• Cold Temperature * MeSH
• Psychrobacter enzymology   genetics   growth & development   physiology   MeSH
• Substrate Specificity MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Bacterial Proteins MeSH
• haloalkane dehalogenase MeSH Browser
• Hydrolases MeSH

Haloalkane dehalogenases make up an important class of hydrolytic enzymes which catalyse the cleavage of carbon-halogen bonds in halogenated aliphatic compounds. There is growing interest in these enzymes owing to their potential use in environmental and industrial applications. The haloalkane dehalogenase DhaA from Rhodococcus rhodochrous NCIMB 13064 can slowly detoxify the industrial pollutant 1,2,3-trichloropropane (TCP). Structural analysis of this enzyme complexed with target ligands was conducted in order to obtain detailed information about the structural limitations of its catalytic properties. In this study, the crystallization and preliminary X-ray analysis of complexes of wild-type DhaA with 2-propanol and with TCP and of complexes of the catalytically inactive variant DhaA13 with the dye coumarin and with TCP are described. The crystals of wild-type DhaA were plate-shaped and belonged to the triclinic space group P1, while the variant DhaA13 can form prism-shaped crystals belonging to the orthorhombic space group P2(1)2(1)2(1) as well as plate-shaped crystals belonging to the triclinic space group P1. Diffraction data for crystals of wild-type DhaA grown from crystallization solutions with different concentrations of 2-propanol were collected to 1.70 and 1.26 Å resolution, respectively. A prism-shaped crystal of DhaA13 complexed with TCP and a plate-shaped crystal of the same variant complexed with the dye coumarin diffracted X-rays to 1.60 and 1.33 Å resolution, respectively. A crystal of wild-type DhaA and a plate-shaped crystal of DhaA13, both complexed with TCP, diffracted to atomic resolutions of 1.04 and 0.97 Å, respectively.

• MeSH
• 2-Propanol MeSH
• Bacterial Proteins chemistry   MeSH
• X-Ray Diffraction MeSH
• Hydrolases chemistry   genetics   metabolism   MeSH
• Hydrolysis MeSH
• Isoenzymes chemistry   genetics   MeSH
• Catalysis MeSH
• Crystallization MeSH
• Crystallography, X-Ray methods   MeSH
• Ligands MeSH
• Propane analogs & derivatives   MeSH
• Rhodococcus enzymology   genetics   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Names of Substances
• 1,2,3-trichloropropane MeSH Browser
• 2-Propanol MeSH
• Bacterial Proteins MeSH
• haloalkane dehalogenase MeSH Browser
• Hydrolases MeSH
• Isoenzymes MeSH
• Ligands MeSH
• Propane MeSH

The enzyme DhaA from Rhodococcus rhodochrous NCIMB 13064 belongs to the haloalkane dehalogenases, which catalyze the hydrolysis of haloalkanes to the corresponding alcohols. The haloalkane dehalogenase DhaA and its variants can be used to detoxify the industrial pollutant 1,2,3-trichloropropane (TCP). Three mutants named DhaA04, DhaA14 and DhaA15 were constructed in order to study the importance of tunnels connecting the buried active site with the surrounding solvent to the enzymatic activity. All protein mutants were crystallized using the sitting-drop vapour-diffusion method. The crystals of DhaA04 belonged to the orthorhombic space group P2(1)2(1)2(1), while the crystals of the other two mutants DhaA14 and DhaA15 belonged to the triclinic space group P1. Native data sets were collected for the DhaA04, DhaA14 and DhaA15 mutants at beamline X11 of EMBL, DESY, Hamburg to the high resolutions of 1.30, 0.95 and 1.15 A, respectively.

• MeSH
• Bacterial Proteins chemistry   genetics   MeSH
• DNA Primers MeSH
• Protein Conformation MeSH
• Crystallization MeSH
• Crystallography, X-Ray MeSH
• Mutation MeSH
• Rhodococcus chemistry   MeSH
• Base Sequence MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Bacterial Proteins MeSH
• DNA Primers MeSH