Biochemical and Structural Characterization of a Schiff Base in the Radical-Mediated Biosynthesis of 4-Demethylwyosine by TYW1.

ABSTRACT: TYW1 is a radical S-adenosyl-l-methionine (SAM) enzyme that catalyzes the condensation of pyruvate and N-methylguanosine to form the posttranscriptional modification, 4-demethylwyosine, in situ on transfer RNA (tRNA). Two mechanisms have been proposed for this transformation, with one of the possible mechanisms invoking a Schiff base intermediate formed between a conserved lysine residue and pyruvate. Utilizing a combination of mass spectrometry and X-ray crystallography, we have obtained evidence to support the formation of a Schiff base lysine adduct in TYW1. When ¹³C labeled pyruvate is used, the mass shift of the adduct matches that of the labeled pyruvate, indicating that pyruvate is the source of the adduct. Furthermore, a crystal structure of TYW1 provides visualization o

SUBMITTER: Grell TAJ 

PROVIDER: S-EPMC5994729 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature