Insights into the Mechanism of Installation of 5-Carboxymethylaminomethyl Uridine Hypermodification by tRNA-Modifying Enzymes MnmE and MnmG.

ABSTRACT: The evolutionarily conserved bacterial proteins MnmE and MnmG (and their homologues in Eukarya) install a 5-carboxymethylaminomethyl (cmnm⁵) or a 5-taurinomethyl (τm⁵) group onto wobble uridines of several tRNA species. The Escherichia coli MnmE binds guanosine-5'-triphosphate (GTP) and methylenetetrahydrofolate (CH₂THF), while MnmG binds flavin adenine dinucleotide (FAD) and a reduced nicotinamide adenine dinucleotide (NADH). Together with glycine, MnmEG catalyzes the installation of cmnm⁵ in a reaction that also requires hydrolysis of GTP. In this letter, we investigated key steps of the MnmEG reaction using a combination of biochemical techniques. We show multiple lines of evidence supporting flavin-iminium FADH[N⁵═CH_2</

SUBMITTER: Bommisetti P 

PROVIDER: S-EPMC10723064 | biostudies-literature | 2023 Dec

REPOSITORIES: biostudies-literature