Core dinoflagellate genomes contain a fifth nucleotide base, 5-hydroxymethyl uracil (5hmU). While there are several hypotheses for how this base is synthesized or how it gets incorporated into the genome, the exact synthetic mechanism has yet to be determined. We identified a transcript for a hypothetical thymine dioxygenase enzyme in the dinoflagellate Amphidinium carterae that could possibly combine thymine, 2-oxoglutarate, and oxygen to produce 5hmU, succinate, and carbon dioxide. In addition, the predicted protein structure and function of the transcript are consistent with other dioxygenase enzymes. Results generated in this study suggest that this transcript is highly conserved across core dinoflagellates as well as the broader Dinoflagellata phylum. Our findings ultimately introduce the possibility for algal bloom mitigation strategies highly specific to dinoflagellate targets should the knockdown or inhibition of thymine dioxygenase prove lethal in dinoflagellates.
Jolly et al. (Fri,) studied this question.