Association of Missense Mutations in Epoxyalkane Coenzyme M Transferase with Adaptation of Mycobacterium sp. Strain JS623 to Growth on Vinyl Chloride
| Autor: | Yang Oh Jin, Samantha Cheung, Timothy E. Mattes, Nicholas V. Coleman |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
DNA
Bacterial Aerobic bacteria Molecular Sequence Data Mutant Mutation Missense Vinyl Chloride Gene Expression Coenzyme M Applied Microbiology and Biotechnology Mycobacterium Microbiology chemistry.chemical_compound Bacterial Proteins Cloning Molecular Enzymology and Protein Engineering Ecology biology Mycobacterium smegmatis Wild type Sequence Analysis DNA Ethylenes biology.organism_classification Carbon-Sulfur Lyases Amino Acid Substitution chemistry Heterologous expression Energy source Oxidation-Reduction Water Pollutants Chemical Bacteria Food Science Biotechnology |
| Zdroj: | Applied and Environmental Microbiology. 76:3413-3419 |
| ISSN: | 1098-5336 0099-2240 |
| DOI: | 10.1128/aem.01320-09 |
| Popis: | Vinyl chloride (VC) is a toxic groundwater pollutant associated with plastic manufacture and chlorinated solvent use. Aerobic bacteria that grow on VC as a carbon and energy source can evolve in the laboratory from bacteria that grow on ethene, but the genetic changes involved are unknown. We investigated VC adaptation in two variants (JS623-E and JS623-T) of the ethene-oxidizing Mycobacterium strain JS623. Missense mutations in the EtnE gene developed at two positions (W243 and R257) in cultures exposed to VC but not in cultures maintained on ethene. Epoxyalkane-coenzyme M transferase (EaCoMT) activities in cell extracts of JS623-E and JS623-T (150 and 645 nmol/min/mg protein, respectively) were higher than that of wild-type JS623 (74 nmol/min/mg protein), and in both variant cultures epoxyethane no longer accumulated during growth on ethene. The heterologous expression of two variant etnE alleles (W243G [ etnE1 ] and R257L [ etnE2 ]) from strain JS623 in Mycobacterium smegmatis showed that they had 42 to 59% higher activities than the wild type. Recombinant JS623 cultures containing mutant EtnE genes cloned in the vector pMV261 adapted to growth on VC more rapidly than the wild-type JS623 strain, with incubation times of 60 days (wild type), 1 day (pMV etnE1 ), and 35 days (pMV etnE2 ). The JS623(pMV etnE ) culture did not adapt to VC after more than 60 days of incubation. Adaptation to VC in strain JS623 is consistently associated with two particular missense mutations in the etnE gene that lead to higher EaCoMT activity. This is the first report to pinpoint a genetic change associated with the transition from cometabolic to growth-linked VC oxidation in bacteria. |
| Databáze: | OpenAIRE |
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