A cyanobacterial adenine prenyltransferase enables longer-chain N6 prenylation

Adenine, a ubiquitous nucleobase found in biomolecules such as nucleic acids, cofactors, and signaling molecules, mediates diverse molecular interactions. Here, we identify TvAPT, an adenine prenyltransferase from the cyanobacterium Trichormus variabilis NIES-23. TvAPT efficiently catalyzes the unprecedented N6-prenylation of adenine-containing substrates using extended C10 and C15 prenyl donors, whereas canonical adenine prenyltransferases are generally limited to C5-dimethylallylation. X-ray structural analyses and protein engineering revealed that an enlarged prenyl-binding pocket enables the accommodation of extended prenyl donors, providing a structural basis for rationally tuning prenyl-donor preference. Together, these findings establish TvAPT as an adenine prenyltransferase that accepts a range of adenine-containing substrates, with a preference for nucleoside 5-monophosphates. Beyond expanding the known catalytic scope of adenine prenyltransferases, TvAPT provides access to nucleotide derivatives with enhanced membrane permeability and analogues of plant signaling molecules.