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Mechanistic Studies of the Radical S-Adenosyl-L-methionine Enzyme 4-Demethylwyosine Synthase Reveal the Site of Hydrogen Atom Abstraction.

ABSTRACT: TYW1 catalyzes the formation of 4-demethylwyosine via the condensation of N-methylguanosine (m¹G) with carbons 2 and 3 of pyruvate. In this study, labeled transfer ribonucleic acid (tRNA) and pyruvate were utilized to determine the site of hydrogen atom abstraction and regiochemistry of the pyruvate addition. tRNA containing a ²H-labeled m¹G methyl group was used to identify the methyl group of m¹G as the site of hydrogen atom abstraction by 5'-deoxyadenosyl radical. [2-¹³C?-3,3,3-²H?]Pyruvate was used to demonstrate retention of all the pyruvate protons, indicating that C2 of pyruvate forms the bridging carbon of the imidazoline ring and C3 the methyl.

SUBMITTER: Young AP

PROVIDER: S-EPMC4753065 | biostudies-other | 2015 Jun

REPOSITORIES: biostudies-other

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Mechanistic Studies of the Radical S-Adenosyl-L-methionine Enzyme 4-Demethylwyosine Synthase Reveal the Site of Hydrogen Atom Abstraction.

Young Anthony P AP Bandarian Vahe V

Biochemistry 20150608 23

TYW1 catalyzes the formation of 4-demethylwyosine via the condensation of N-methylguanosine (m¹G) with carbons 2 and 3 of pyruvate. In this study, labeled transfer ribonucleic acid (tRNA) and pyruvate were utilized to determine the site of hydrogen atom abstraction and regiochemistry of the pyruvate addition. tRNA containing a ²H-labeled m¹G methyl group was used to identify the methyl group of m¹G as the site of hydrogen atom abstraction by 5'-deoxyadenosyl radical. [2-¹³C₁-3,3,3-²H₃]Pyruvate w ...[more]

PMID: 26052987

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