Figure 1.

Cartoon depiction of ATE1-mediated post-translational arginylation. Arginyl-tRNA transferases (ATE1; lavender) catalyze the energy-independent transfer of the amino acid Arg (R, green circle) from an aminoacylated tRNA (gray) to an acceptor protein (rainbow colored from blue to red, N-terminus to C-terminus, respectively). The process of arginylation occurs most frequently at the N-terminus of a polypeptide, although more recent studies have shown that internal (midchain) arginylation is also possible.