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
• bakteriální proteiny chemie   genetika   metabolismus   MeSH
• fyziologická adaptace * MeSH
• hydrolasy chemie   genetika   metabolismus   MeSH
• kinetika MeSH
• koncentrace vodíkových iontů MeSH
• nízká teplota * MeSH
• Psychrobacter enzymologie   genetika   růst a vývoj   fyziologie   MeSH
• substrátová specifita MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bakteriální proteiny MeSH
• haloalkane dehalogenase MeSH Prohlížeč
• hydrolasy MeSH

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.

• MeSH
• Agrobacterium tumefaciens enzymologie   genetika   metabolismus   MeSH
• alkany metabolismus   MeSH
• DNA bakterií chemie   genetika   MeSH
• estery metabolismus   MeSH
• hydrolasy genetika   izolace a purifikace   metabolismus   MeSH
• molekulární sekvence - údaje MeSH
• multimerizace proteinu MeSH
• rostliny mikrobiologie   MeSH
• sekvenční analýza DNA MeSH
• stereoizomerie MeSH
• substrátová specifita MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alkany MeSH
• DNA bakterií MeSH
• estery MeSH
• haloalkane dehalogenase MeSH Prohlížeč
• hydrolasy MeSH

This study focuses on two representatives of experimentally uncharacterized haloalkane dehalogenases from the subfamily HLD-III. We report biochemical characterization of the expression products of haloalkane dehalogenase genes drbA from Rhodopirellula baltica SH1 and dmbC from Mycobacterium bovis 5033/66. The DrbA and DmbC enzymes show highly oligomeric structures and very low activities with typical substrates of haloalkane dehalogenases.

• MeSH
• Bacteria enzymologie   MeSH
• cirkulární dichroismus MeSH
• DNA bakterií chemie   genetika   MeSH
• hydrolasy chemie   genetika   izolace a purifikace   metabolismus   MeSH
• molekulární sekvence - údaje MeSH
• multimerizace proteinu MeSH
• Mycobacterium bovis enzymologie   MeSH
• sekvenční analýza DNA MeSH
• substrátová specifita MeSH
• terciární struktura proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA bakterií MeSH
• haloalkane dehalogenase MeSH Prohlížeč
• hydrolasy MeSH

Haloalkane dehalogenases are enzymes that catalyze the cleavage of the carbon-halogen bond by a hydrolytic mechanism. Genomes of Mycobacterium tuberculosis and M. bovis contain at least two open reading frames coding for the polypeptides showing a high sequence similarity with biochemically characterized haloalkane dehalogenases. We describe here the cloning of the haloalkane dehalogenase genes dmbA and dmbB from M. bovis 5033/66 and demonstrate the dehalogenase activity of their translation products. Both of these genes are widely distributed among species of the M. tuberculosis complex, including M. bovis, M. bovis BCG, M. africanum, M. caprae, M. microti, and M. pinnipedii, as shown by the PCR screening of 48 isolates from various hosts. DmbA and DmbB proteins were heterologously expressed in Escherichia coli and purified to homogeneity. The DmbB protein had to be expressed in a fusion with thioredoxin to obtain a soluble protein sample. The temperature optimum of DmbA and DmbB proteins determined with 1,2-dibromoethane is 45 degrees C. The melting temperature assessed by circular dichroism spectroscopy of DmbA is 47 degrees C and DmbB is 57 degrees C. The pH optimum of DmbA depends on composition of a buffer with maximal activity at 9.0. DmbB had a single pH optimum at pH 6.5. Mycobacteria are currently the only genus known to carry more than one haloalkane dehalogenase gene, although putative haloalkane dehalogenases can be inferred in more then 20 different bacterial species by comparative genomics. The evolution and distribution of haloalkane dehalogenases among mycobacteria is discussed.

• MeSH
• bakteriální proteiny chemie   genetika   izolace a purifikace   metabolismus   MeSH
• hydrolasy chemie   genetika   izolace a purifikace   metabolismus   MeSH
• klonování DNA * MeSH
• koncentrace vodíkových iontů MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• Mycobacterium bovis enzymologie   genetika   MeSH
• Mycobacterium klasifikace   enzymologie   genetika   MeSH
• sekvenční analýza DNA MeSH
• skot MeSH
• stabilita enzymů MeSH
• teplota MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bakteriální proteiny MeSH
• haloalkane dehalogenase MeSH Prohlížeč
• hydrolasy MeSH