deoxyhypusine synthase activity obsolete deoxyhypusine biosynthetic process from spermidine true biological_process deoxyhypusine biosynthetic process from spermidine, using deoxyhypusine synthase spermidine breakdown to deoxyhypusine, using deoxyhypusine synthase deoxyhypusine anabolism from spermidine, using deoxyhypusine synthase deoxyhypusine formation from spermidine, using deoxyhypusine synthase GO:0050983 deoxyhypusine biosynthesis from spermidine, using deoxyhypusine synthase spermidine catabolic process to deoxyhypusine, using deoxyhypusine synthase spermidine degradation to deoxyhypusine, using deoxyhypusine synthase OBSOLETE. The chemical reactions resulting in the formation of deoxyhypusine from spermidine by the enzyme [eIF-5A]-deoxyhypusine synthase. The reaction occurs in four steps: 1. spermidine + NAD+ = dehydrospermidine + NADH + H+; 2. dehydrospermidine + [enzyme]-lysine = 1,3-diaminopropane + [enzyme]-lysine-N6=CH(CH2)3NH2; 3. [enzyme]-lysine-N6=CH(CH2)3NH2 = [eIF-5A]-lysine-N6=CH(CH2)3NH2; 4. [eIF-5A]-lysine-N6=CH(CH2)3NH2 + NADH + H+ = [eIF-5A]-deoxyhypusine + NAD+. The reason for obsoletion is that although GO:0050983 is described as a multistep process, the entire reaction is carried out by a single enzyme, therefore was replacey by the molecular function GO:0034038 deoxyhypusine synthase activity.