Flavin metamorphosis: cofactor transformation through prenylation

Abstract

Prenylated flavin (prFMN) is a recently discovered cofactor that underpins catalysis in the ubiquitous microbial UbiDX system. UbiX acts as a flavin prenyltransferase while UbiD is a prFMN-dependent reversible (de)carboxylase. The extensive modification of flavin by prenylation, and the consecutive oxidation to the prFMN^iminium azomethine ylide, leads to cofactor metamorphosis. While prFMN is no longer able to perform N5-based classical flavin chemistry, it is capable of forming cycloadducts with dipolarophiles, long-lived C4a-based radical species as well as undergoing extensive light driven isomerization. An ever-expanding range of distinct prFMN forms hints at the possibility of novel prFMN driven biochemistry yet to be discovered.