A promiscuous cytochrome P450 aromatic -demethylase for lignin bioconversion
- Mallinson, Sam J. B. [ Molecular Biophysics, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, UK ]
- Machovina, Melodie M. [ Montana State University: Chemistry & Biochemistry ] [ National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, USA ]
- Silveira, Rodrigo L. [ National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, USA ] [ Institute of Chemistry, University of Campinas, Campinas, Sao Paulo, Brazil ]
- Garcia-Borras, Marc [ Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA, USA ]
- Gallup, Nathan [ National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, USA ] [ Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA, USA ]
- Johnson, Christopher W. [ National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, USA ]
- Allen, Mark D. [ Molecular Biophysics, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, UK ]
- Skaf, Munir S. [ Institute of Chemistry, University of Campinas, Campinas, Sao Paulo, Brazil ]
- Crowley, Michael F. [ Biosciences Center, National Renewable Energy Laboratory, Golden, CO, USA ]
- Neidle, Ellen L. [ Department of Microbiology, University of Georgia, Athens, GA, USA ]
- Houk, Kendall N. [ Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA, USA ]
- Beckham, Gregg T. [ National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, USA ]
- DuBois, Jennifer L. [ Montana State University: Chemistry & Biochemistry ]
- McGeehan, John E. [ Molecular Biophysics, School of Biological Sciences, Institute of Biological and Biomedical Sciences, University of Portsmouth, Portsmouth, UK ]
Microbial aromatic catabolism offers a promising approach to convert lignin, a vast source of renewable carbon, into useful products. Aryl-O-demethylation is an essential biochemical reaction to ultimately catabolize coniferyl and sinapyl lignin-derived aromatic compounds, and is often a key bottleneck for both native and engineered bioconversion pathways. Here, we report the comprehensive characterization of a promiscuous P450 aryl-O-demethylase, consisting of a cytochrome P450 protein from the family CYP255A (GcoA) and a three-domain reductase (GcoB) that together represent a new two-component P450 class. Though originally described as converting guaiacol to catechol, we show that this system efficiently demethylates both guaiacol and an unexpectedly wide variety of lignin-relevant monomers. Structural, biochemical, and computational studies of this novel two-component system elucidate the mechanism of its broad substrate specificity, presenting it as a new tool for a critical step in biological lignin conversion.