Reannotation of Fly Amanita l-DOPA Dioxygenase Gene Enables Its Cloning and Heterologous Expression.

The l-DOPA dioxygenase of (AmDODA) participates in the biosynthesis of betalain- and hygroaurin-type natural pigments. AmDODA is encoded by the gene, whose DNA sequence was inferred from cDNA and gDNA libraries almost 30 years ago. However, reports on its heterologous expression rely on either the original 5'-truncated cDNA plasmid or artificial gene synthesis. We provide unequivocal evidence that the heterologous expression of AmDODA from specimens is not possible by using the coding sequence previously inferred for . Here, we rectify and reannotate the full-length coding sequence for AmDODA and express a 205-aa His-tagged active enzyme, which was used to produce the l-DOPA hygroaurin, a rare fungal pigment. Moreover, AmDODA and other isozymes from bacteria were submitted to folding using deep learning algorithms, and their putative active sites were inferred and compared. The wide catalytic pocket of AmDODA and the presence of the His-His-His and His-His-Asp motifs can provide insight into the dual cleavage of l-DOPA at positions 2,3 and 4,5 as per the mechanism proposed for nonheme dioxygenases.