Characterization of the N-Hydroxylating Monooxygenase TheA from Thermocrispum agreste Reveals a Broad Substrate Spectrum.

ABSTRACT: The N-hydroxylating monooxygenase (NMO) TheA from Thermocrispum agreste catalyzes the N-hydroxylation step of l-ornithine, which is the first step in the thermochelin siderophore biosynthesis. Characterization of this enzyme revealed a significant thermostability up to 50 °C and activity with the non-native substrate d-ornithine with kinetic parameters (K_m = 4.06 ± 0.31 mM, k_cat = 0.057 ± 0.001 s^-1, and k_cat/K_m = 0.007 s^-1mM^-1) and a coupling rate of 81%. The enzyme is applied in a one-pot reaction with a formate dehydrogenase variant for NADPH regeneration and catalase for H₂O₂ detoxification. Optimization of the reaction conditions resulted in activity with various non-native substrates su

SUBMITTER: Maier A 

PROVIDER: S-EPMC12498188 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature