Enrichment of Functional Redox Reactive Proteins and Identification by Mass Spectrometry Results in Several Terminal Fe(III)-reducing Candidate Proteins in Shewanella oneidensis MR-1.
Identification of the proteins directly involved in microbial metal-reduction is important to understanding the biochemistry involved in heavy metal reduction/immobilization and the ultimate cleanup of DOE contaminated sites. Although previous strategies for the identification of these proteins have traditionally required laborious protein purification/characterization of metal-reducing capability, activity is often lost before the final purification step, thus creating a significant knowledge gap. In the current study, subcellular fractions of S. oneidensis MR-1 were enriched for Fe(III)-NTA reducing proteins in a single step using several orthogonal column matrices. The protein content of eluted fractions that demonstrated activity were determined by ultra high pressure liquid chromatography coupled with tandem mass spectrometry (LCMS/ MS). A comparison of the proteins identified from active fractions in all separations produced 30 proteins that may act as the terminal electron-accepting protein for Fe(III)-reduction. These include MtrA, MtrB, MtrC and OmcA as well as a number of other proteins not previously associated with Fe(III)-reduction. This is the first report of such an approach where the laborious procedures for protein purification are not required for identification of metal-reducing proteins. Such work provides the basis for a similar approach with other cultured organisms as well as analysis of sediment and groundwater samples from biostimulation efforts at contaminated sites.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 902950
- Report Number(s):
- PNNL-SA-52214; JMIMDQ; 12094; KP1302000
- Journal Information:
- Journal of Microbiological Methods, 68(2):367-375, Vol. 68, Issue 2; ISSN 0167-7012
- Country of Publication:
- United States
- Language:
- English
Similar Records
Metal Reduction and Protein Secretion Genes Required for Iodate Reduction by Shewanella oneidensis
Kinetics of Reduction of Fe(III) Complexes by Outer Membrane Cytochromes MtrC and OmcA of Shewanella oneidensis MR-1