Involved in the post-translational conjugation of arginine to the N-terminal aspartate or glutamate of a protein. This arginylation is required for degradation of the protein via the ubiquitin pathway. Component of the N-end rule pathway with ATE2 and PRT6 (PubMed:19255443, PubMed:19620738, PubMed:22020282). The N-end rule pathway regulates seed after-ripening, seedling sugar sensitivity, seedling lipid breakdown, and abscisic acid (ABA) sensitivity of germination (PubMed:19255443). The end-rule pathway regulates various aspects of leaf and shoot development (PubMed:19620738). Involved in the oxygen-dependent N-arginylation of RAP2-12, an activator of hypoxic gene expression. This N-terminal modification leads to ubiquitination by PRT6 and subsequent degradation of RAP2-12 under aerobic conditions (PubMed:22020282). Has an important role in the progression of leaf senescence (PubMed:12366806). Involved in disease resistance (PubMed:27173012). The end-rule pathway plays a role in regulating the timing and amplitude of the immune response following infection with the bacterial pathogen Pseudomonas syringae pv tomato (PubMed:27173012). Regulates the biosynthesis of plant-defense metabolites such as glucosinolates, and the biosynthesis and response to the phytohormone jasmonate (JA), which plays a key role in plant immunity (PubMed:27173012). an N-terminal L-alpha-aminoacyl-[protein] + L-arginyl-tRNA(Arg) = H(+) + N-terminal L-arginyl-L-amino acid-[protein] + tRNA(Arg) Delayed leaf senescence phenotype (PubMed:12366806). The double mutants ate1 and ate2 show reduced seed germination potential and inhibition of seedling establishment by sucrose (PubMed:19255443). The double mutants ate1 and ate2 exhibit abnormal shoot and leaf development (PubMed:19620738). Belongs to the R-transferase family.