L-histidyl-[translation elongation factor 2] + S-adenosyl-L-methionine <=> 2-[(3S)-amino-3-carboxypropyl]-L-histidyl-[translation elongation factor 2] + S-methyl-5'-thioadenosine + H(+)
l-histidyl-[translation elongation factor 2] + s-adenosyl-l-methionine <=> 2-[(3s)-amino-3-carboxypropyl]-l-histidyl-[translation elongation factor 2] + s-methyl-5'-thioadenosine + h(+)