Related Experiment Videos
Arsenite oxidase, an ancient bioenergetic enzyme
Evelyne Lebrun1, Myriam Brugna, Frauke Baymann
1Laboratoire de Bioénergétique et Ingénierie des Protéines, Institut de Biologie Structurale et Microbiologie, Marseille Cedex, France.
Molecular Biology and Evolution
|April 8, 2003
Summary
Arsenite oxidase operons are found in Archaea and Bacteria, suggesting an ancient origin before their divergence. This enzyme is membrane-associated via the tat system and a Rieske subunit helix.
Area of Science:
- Microbiology
- Biochemistry
- Evolutionary Biology
Background:
- Arsenite oxidase is a key enzyme in arsenic metabolism.
- Its genomic distribution and membrane association mechanisms require further elucidation.
Purpose of the Study:
- To identify arsenite oxidase operons in diverse microbial genomes.
- To investigate the membrane association and evolutionary origins of arsenite oxidase.
Main Methods:
- BLAST searches for arsenite oxidase genes.
- Sequence analysis and phylogenetic tree construction.
- Biochemical and biophysical characterization of the enzyme.
Main Results:
- Arsenite oxidase operons are present in both Archaea and Bacteria.
- The enzyme is transported via the twin-arginine transport (tat) system and anchored by a Rieske subunit transmembrane helix.
- Phylogenetic analyses suggest an early evolutionary origin predating Archaea-Bacteria divergence.
Conclusions:
- Arsenite oxidase is an ancient enzyme with a conserved membrane association mechanism.
- The findings provide insights into microbial arsenic detoxification pathways and early microbial evolution.