JC8.4 encodes a cytosine deaminase orthologous to Saccharomyces cerevisiae Tad2p, a deaminase that lies, evolutionarily, between cytidine and adenosine deaminases and deaminates adenosine residues in the anticodon of specific yeast tRNAs; loss of JC8.4 activity via RNAi has been reported to result in partially penetrant embryonic lethality.
Predicted to enable tRNA-specific adenosine-34 deaminase activity. Predicted to be involved in tRNA wobble adenosine to inosine editing. Is an ortholog of human ADAT2 (adenosine deaminase tRNA specific 2).