Desulfotomaculum reducens MI-1 is a Firmicute strain capable of reducing a variety of heavy metal ions and has a great potential in heavy metal bioremediation.We recently identified Dred_2421 as a potential iron reductase through proteomic study of D. reducens. The current study examines its iron-reduction mechanism. Dred_2421, like its close homolog from Escherichia coli (2, 4-dienoyl-CoA reductase), has an FMN-binding N-terminal domain (NTD), an FAD-binding C-terminal domain (CTD), and a 4Fee4S cluster between the two domains. To understand the mechanism of the iron-reduction activity and the role of each domain, we generated a series of variants for each domain and investigated their iron reduction activity. Our results suggest that CTD is the main contributor of the iron-reduction activity, and that NTD and the 4Fee4S cluster are not directly involved in such activity. This study provides a mechanistic understanding of the ironereductase activity of Dred_2421 and may also help to elucidate other physiological activities this enzyme may have.
Revised: March 18, 2016 |
Published: October 8, 2015
Citation
Li Z., D.D. Kim, O.D. Nelson, A.E. Otwell, R.E. Richardson, S.J. Callister, and H. Lin. 2015.Molecular dissection of a putative iron reductase from Desulfotomaculum reducens MI-1.Biochemical and Biophysical Research Communications 467, no. 3:503-508.PNNL-SA-115336.doi:10.1016/j.bbrc.2015.10.016