2bfn
The crystal structure of the complex of the haloalkane dehalogenase LinB with the product of dehalogenation reaction 1,2-dichloropropane.
Structural highlights
FunctionLINB_SPHJU Catalyzes hydrolytic cleavage of carbon-halogen bonds in halogenated aliphatic compounds, leading to the formation of the corresponding primary alcohols, halide ions and protons. Has a broad substrate specificity since not only monochloroalkanes (C3 to C10) but also dichloroalkanes (> C3), bromoalkanes, and chlorinated aliphatic alcohols are good substrates (PubMed:9293022, PubMed:10100638). Shows almost no activity with 1,2-dichloroethane, but very high activity with the brominated analog (PubMed:9293022). Is involved in the degradation of the important environmental pollutant gamma-hexachlorocyclohexane (gamma-HCH or lindane) as it also catalyzes conversion of 1,3,4,6-tetrachloro-1,4-cyclohexadiene (1,4-TCDN) to 2,5-dichloro-2,5-cyclohexadiene-1,4-diol (2,5-DDOL) via the intermediate 2,4,5-trichloro-2,5-cyclohexadiene-1-ol (2,4,5-DNOL) (PubMed:7691794). This degradation pathway allows S.japonicum UT26 to grow on gamma-HCH as the sole source of carbon and energy.[1] [2] [3] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed1,2,3-Trichloropropane (TCP) is a highly toxic and recalcitrant compound. Haloalkane dehalogenases are bacterial enzymes that catalyze the cleavage of a carbon-halogen bond in a wide range of organic halogenated compounds. Haloalkane dehalogenase LinB from Sphingobium japonicum UT26 has, for a long time, been considered inactive with TCP, since the reaction cannot be easily detected by conventional analytical methods. Here we demonstrate detection of the weak activity (k(cat) = 0.005 s(-1)) of LinB with TCP using X-ray crystallography and microcalorimetry. This observation makes LinB a useful starting material for the development of a new biocatalyst toward TCP by protein engineering. Microcalorimetry is proposed to be a universal method for the detection of weak enzymatic activities. Detection of these activities is becoming increasingly important for engineering novel biocatalysts using the scaffolds of proteins with promiscuous activities. Weak activity of haloalkane dehalogenase LinB with 1,2,3-trichloropropane revealed by X-Ray crystallography and microcalorimetry.,Monincova M, Prokop Z, Vevodova J, Nagata Y, Damborsky J Appl Environ Microbiol. 2007 Mar;73(6):2005-8. Epub 2007 Jan 26. PMID:17259360[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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