Reaction: Met-Arg-Tyr-Leu-His + nitric oxide + O2 + reduced ferredoxin + H+ = Met-Arg-(3-NO2)-Tyr-Leu-His + H2O + oxidized ferredoxin
Glossary: (3-NO2)-Tyr = 3-nitro-L-tyrosine
Other name(s): rufO (gene name); 3-nitro-tyrosine synthase
Systematic name: Met-Arg-Tyr-Leu-His,nitric oxide, reduced ferredoxin:oxygen oxidoreductase (3-nitro-L-tyrosine-forming)
Comments: A cytochrome P-450 (heme-thiolate) enzyme characterized from the bacterium Streptomyces atratus. The enzyme participates in biosynthesis of rufomycins, circular heptapeptides with anti-mycobacterial activity. The enzyme requires ferredoxin as its electron donor and catalyses a reaction in which nitric oxide is oxidized to a nitro group and inserted into L-tyrosine present in the ribosomally-synthesized peptide Met-Arg-Tyr-Leu-His. The L-tyrosine is nitrosylated at the 3 position.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Tomita, H., Katsuyama, Y., Minami, H. and Ohnishi, Y. Identification and characterization of a bacterial cytochrome P450 monooxygenase catalyzing the 3-nitration of tyrosine in rufomycin biosynthesis. J. Biol. Chem. 292 (2017) 15859-15869. [PMID: 28774961]
2. Jordan, S., Li, B., Traore, E., Wu, Y., Usai, R., Liu, A., Xie, Z.R. and Wang, Y. Structural and spectroscopic characterization of RufO indicates a new biological role in rufomycin biosynthesis. J. Biol. Chem. 299 (2023) 105049. [PMID: 37451485]
3. Dratch, B.D., McWhorter, K.L., Blue, T.C., Jones, S.K., Horwitz, S.M. and Davis, K.M. Insights into substrate recognition by the unusual nitrating enzyme RufO. ACS Chem. Biol. 18 (2023) 1713-1718. [PMID: 37555759]
4. Padva, L., Zimmer, L., Gullick, J., Zhao, Y., Sasi, V.M., Schittenhelm, R.B., Jackson, C.J., Cryle, M.J. and Crüsemann, M. Ribosomal pentapeptide nitration for non-ribosomal peptide antibiotic precursor biosynthesis. Chem 11 (2025) 102438.
5. Nolan, K., Usai, R., Li, B., Jordan, S. and Wang, Y. Molecular basis for peptide nitration by a novel cytochrome P450 enzyme in RiPP biosynthesis. ACS Catal. 15 (2025) 10391-10404. [PMID: 40568218]