title: A non-dechlorinating strain of Dehalospirillum multivorans: evidence for a key role of the corrinoid cofactor in the synthesis of an active tetrachloroethene dehalogenase.
abstract: A strain of Dehalosprillum multivorans, designated strain N, was isolated from the same source as the formerly described tetrachloroethene (PCE)-dechlorinating D. multivorans, herein after referred to as strain K. Neither growing cells nor cell extracts of strain N were able to dechlorinate PCE. The pceA and pceB genes encoding for the PCE-reductive dehalogenase were detected in cells of strain N; and they were 100% homologous to the corresponding genes of strain K. Since the PCE dehalogenase of D. multivorans strain K contains a corrinoid cofactor, the corrinoids of strain N cells were extracted. Analysis of the corrinoids revealed the absence of the specific corrinoid, which is the cofactor of the PCE dehalogenase of strain K cells. RT-PCR of mRNA indicated that the pceA gene was transcribed in strain N cells to a far lower extent than the pceA gene of strain K under the same experimental conditions. Western blot analysis of crude extracts of strain N showed that, if at all, an insignificant amount of the apoprotein of the PCE dehalogenase was present. The results indicate that the inability of strain N to dechlorinate is due to the absence of the corrinoid cofactor of the enzyme mediating PCE dechlorination.
authors.affiliation: Institut für Mikrobiologie, Lehrstuhl für Angewandte und Okologische Mikrobiologie, FSU Jena, Philosophenweg 12, 07743 Jena, Germany.
authors.forename: Anke
authors.initials: A
authors.lastname: Siebert
authors.forename: Anke
authors.initials: A
authors.lastname: Neumann
authors.forename: Torsten
authors.initials: T
authors.lastname: Schubert
authors.forename: Gabriele
authors.initials: G
authors.lastname: Diekert
mesh_terms: D002851:Chromatography, High Pressure Liquid; D045728:Corrinoids; D020565:Epsilonproteobacteria / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000378:metabolism*; D011166:Porphyrins / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D045728:Corrinoids; D011166:Porphyrins; D010088:Oxidoreductases; C112990:tetrachloroethene dehalogenase