N(omega)-methyl-L-arginyl-[protein] + 2-oxoglutarate + O2 => L-arginyl-[protein] + formaldehyde + succinate + CO2
n(omega)-methyl-l-arginyl-[protein] + 2-oxoglutarate + o2 => l-arginyl-[protein] + formaldehyde + succinate + co2