RufO, a cytochrome P450 (CYP) enzyme, recognition to putative substrates and a redox partner: Binding and structural...

Area of Science:

• Biochemistry
• Enzymology
• Structural Biology

Background:

• RufO is a Cytochrome P450 enzyme crucial for synthesizing the antibacterial compound Rufomycin.
• Understanding RufO's substrate specificity is key to elucidating its biological function and potential applications.

Purpose of the Study:

• To resolve ambiguities regarding RufO's substrate specificity through structural and biophysical analyses.
• To investigate the role of ferredoxin in modulating RufO's activity and substrate recognition.

Main Methods:

• X-ray crystallography to determine the structure of unliganded RufO.
• Isothermal titration calorimetry (ITC) to assess substrate binding and interactions.
• Computational studies to investigate substrate specificity.

Main Results:

• RufO did not recognize monomeric L-tyrosine, contrary to previous reports.
• RufO demonstrated recognition of various putative substrates, particularly those with methyl and nitro groups, indicating a broader substrate scope.
• RufO binds its redox partner CamB with micromolar affinity, enhancing substrate binding approximately 10-fold.

Conclusions:

• RufO appears to be a substrate-promiscuous enzyme.
• The findings suggest potential applications for RufO in the biocatalytic nitration of industrially relevant compounds.