Phenotypic characterisation and genetic complementation of dimethylsulfoxide respiratory mutants of Rhodobacter sphaeroides and Rhodobacter capsulatus |
| |
| Authors: | Tracey C. Bonnett Paul Cobine R. Elizabeth Sockett Alastair G. McEwan |
| |
| Affiliation: | Centre for Metalloprotein Spectroscopy and Biology, School of Biological Sciences. University of East Anglia, Norwich NR4 777, UK; Department of Microbiology, The University of Queensland, Brisbane Qld 4072, Australia; Department of Life Science, University of Nottingham, University Park, Nottingham NG7 2RD, UK |
| |
| Abstract: | Abstract Two chlorate resistant mutants of Rhodobacter sphaeroides were isolated which were deficient in dimethylsulfoxide reductase activity. Immunoblotting experiments showed that the phenotype of these mutants and that of Rhodobacter capsulatus strain DK9, a mutant unable to reduce dimethylsulfoxide, was correlated with low or undetectable levels of the dimethylsulfoxide reductase apoprotein. All three mutants were complemented by a cosmid from a library of Rhodobacter sphaeroides genomic DNA. Further genetic complementation analysis revealed that functions required for restoration of dimethylsulfoxide reductase activity in the Rhodobacter sphaeroides mutants were encoded on an 9 kb EcoR1 DNA fragment derived from this cosmid. Expression of this 9 kb DNA fragment in Escherichia coli showed that it encoded the dimethylsulfoxide reductase structural gene of Rhodobacter sphaeroides . |
| |
| Keywords: | Rhodobacter Dimethylsulfoxide reductase Periplasm Trimethylamine-N-oxide reductase Chlorate resistance |
|
|
