protein-arginine N-methyltransferase activity histone H4R3 methyltransferase activity https://github.com/geneontology/go-ontology/issues/28520 https://github.com/geneontology/go-ontology/issues/30578 Note that the residue position corresponds to the canonical human H4 histone (UniProtKB:P02309); this residue is conserved across all eukaryotes. Note that the initiation methionine is cleaved, so the first residue is S1. histone H4KR3 methylation histone methylase activity (H4-R3 specific) Catalysis of the reaction: S-adenosyl-L-methionine + (histone H4)-arginine (position 3) = S-adenosyl-L-homocysteine + (histone H4)-N-methyl-arginine (position 3). This reaction is the addition of a methyl group to the arginine residue at position 3 of histone H4, producing histone H4R3me. histone H4R3 arginine methylase activity molecular_function histone-arginine N-methyltransferase activity (H4-R3 specific) GO:0044020 histone methyltransferase activity (H4-R3 specific) histone H4 methyltransferase activity