Anaerobic phosphite oxidation - genetic and enzymatic studies
Final Report Abstract
We find that the energy conservation mechanism during anaerobic phosphite oxidation process in D. phosphitoxidans, based on proteomic, native protein enrichment, enzymatic and genomic data proceeds via substrate phosphorylation where the Adenylylsulfate reductase catalyses the formation of ADP from phosphite and AMP in the presence of an oxidized electron acceptor. The previously described spectrophotometric assay for measurement of phosphite-oxidizing enzyme activity in cell-free extracts of D. phosphitoxidans cells with NAD+ or NADP+ as electron acceptors was improved. A further coupled enzymatic assay was developed, as well as a method for separation and quantitation of the reaction products. All specific proteins expressed in the strain only when phosphite was used as electron donor were cloned, over expressed and partially purified. A protocol for the enrichment of the native protein complex involved in anaerobic phosphite oxidation process was developed. The genome of the strain has been sequenced, assembled, automatically annotated and manually curated. A complete metabolic map and analysis of the genome was performed. Several new metabolic pathways found in the genome were confirmed on physiological level. Most of the proteomic data and the protein enrichment, over-expression and purification data will be published in the future, when the native protein purification protocol and the confirmatory data from the assays will be finalized.
Publications
- (2013) Draft genome sequence of Desulfotignum phosphitoxidans DSM 13687 strain FiPS-3. Genome Announc. 1(3)
Poehlein, A., Rolf, D., Simeonova, D.D.
(See online at https://doi.org/10.1128/genomeA.00227-13) - (2013) Life based on phosphite: a genome-guided analysis of Desulfotignum phosphitoxidans. BMC Genomics 14:753
Poehlein, A., Daniel, R., Schink, B., Simeonova, D.D.
(See online at https://doi.org/10.1186/1471-2164-14-753) - Geomicrobial interactions with phosphorus. In: Ehrlich’s Geomicrobiology, 6th ed. H. L. Ehrlich, D. K. Newman, A. Kappler, eds., chapter 13, pp. 265-279, CRC Press, Taylor and Francis, Boca Raton, London, New York (2015)
Schink, B., D. D. Simeonova
