Sequencing and transcriptional analysis of the chlorite dismutase gene of Dechloromonas agitata and its use as a metabolic probe.
The dismutation of chlorite into chloride and O(2) represents a central step in the reductive pathway of perchlorate that is common to all dissimilatory perchlorate-reducing bacteria and is mediated by a single enzyme, chlorite dismutase. The chlorite dismutase gene cld was isolated and sequenced from the perchlorate-reducing bacterium Dechloromonas agitata strain CKB. Sequence analysis identified an open reading frame of 834 bp that would encode a mature protein with an N-terminal sequence identical to that of the previously purified D. agitata chlorite dismutase enzyme. The predicted translation product of the D. agitata cld gene is a protein of 277 amino acids (aa), including a leader peptide of 26 aa. Primer extension analysis identified a single transcription start site directly downstream of an AT-rich region that could represent the -10 promoter region of the D. agitata cld gene. Northern blot analysis indicated that the cld gene was transcriptionally up-regulated when D. agitata cells were grown in perchlorate-reducing versus aerobic conditions. Slot blot hybridizations with a D. agitata cld probe demonstrated the conservation of the cld gene among perchlorate-reducing bacteria. This study represents the first description of a functional gene associated with microbial perchlorate reduction.
D000595:Amino Acid Sequence; D001483:Base Sequence; D020562:Betaproteobacteria / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D015152:Blotting, Northern; D003001:Cloning, Molecular; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000235:genetics*; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D010088:Oxidoreductases; C402794:chlorite dismutase