Discovery, characterization, and synthetic potential of two novel bacterial aryl-alcohol oxidases.
Cinca-Fernando, P., Ascaso-Alegre, C., Sevilla, E., Martinez-Julvez, M., Mangas-Sanchez, J., Ferreira, P.(2024) Appl Microbiol Biotechnol 108: 498-498
- PubMed: 39470785 
- DOI: https://doi.org/10.1007/s00253-024-13314-z
- Primary Citation of Related Structures:  
8RPF, 8RPG - PubMed Abstract: 
The search for novel synthetic tools to prepare industrial chemicals in a safer and greener manner is a continuing challenge in synthetic chemistry. In this manuscript, we report the discovery, characterization, and synthetic potential of two novel aryl-alcohol oxidases from bacteria which are able to oxidize a variety of aliphatic and aromatic alcohols with efficiencies up to 4970 min -1 mM -1 . Both enzymes have shown a reasonable thermostability (thermal melting temperature values of 50.9 and 48.6 °C for ShAAO and SdAAO, respectively). Crystal structures revealed an unusual wide-open entrance to the active-site pockets compared to that previously described for traditional fungal aryl-alcohol oxidases, which could be associated with differences observed in substrate scope, catalytic efficiency, and other functional properties. Preparative-scale reactions and the ability to operate at high substrate loadings also demonstrate the potential of these enzymes in synthetic chemistry with total turnover numbers > 38000. Moreover, their availability as soluble and active recombinant proteins enabled their use as cell-free extracts which further highlights their potential for the large-scale production of carbonyl compounds. KEY POINTS: • Identification and characterization of two novel bacterial aryl-alcohol oxidases • Crystal structures reveal wide-open active-site pockets, impacting substrate scope • Total turnover numbers and cell-free extracts demonstrate the synthetic potential.
Organizational Affiliation: 
Department of Biochemistry and Molecular and Cellular Biology and Institute of Biocomputation and Physics of Complex Systems (BIFI, GBsC-CSIC Joint Unit), University of Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain.