Identification of Laccase Family of Auricularia auricula-judae and Structural Prediction Using Alphafold

Laccase is an enzyme that plays an important role in fungi, including lignin degradation, stress defense, and formation of fruiting bodies. <i>Auricularia auricula-judae</i> is a white-rot fungus in the Basidiomycota phylum, capable of delignifying wood. In this study, seven genes belonging to the laccase family were identified through de novo sequencing, containing Cu-Oxidase, Cu-Oxidase_2, and Cu-Oxidase_3 domains. Subsequently, the physical characteristics, phylogenetic relationships, protein secondary structure, and tertiary structure of the laccase family (<i>AaLac1</i>-<i>AaLac7</i>) were analyzed. Prediction of N-glycosylation sites identified 2 to 10 sites in the laccase family, with <i>AaLac7</i> having the highest number of sites at 10. Sequence alignment and analysis of the laccase family showed high consistency in signature sequences. Phylogenetic analysis confirmed the relationship among laccases within the family, with <i>AaLac3</i>-<i>AaLac4</i> and <i>AaLac5</i>-<i>AaLac6</i> being closely positioned on the tree, exhibiting high similarity in tertiary structure predictions. This study identified and analyzed laccase family genes in <i>Auricularia auricula-judae</i> using de novo sequencing, offering a simple method for identifying and analyzing the laccase family in organisms with unknown genetic information.