Deoxyhypusine synthase

Deoxyhypusine synthase (, spermidine:eIF5A-lysine 4-aminobutyltransferase (propane-1,3-diamine-forming)) is an enzyme with systematic name (eIF5A-precursor)-lysine:spermidine 4-aminobutyltransferase (propane-1,3-diamine-forming). This enzyme catalyses the following chemical reaction


 * [eIF5A-precursor]-lysine + spermidine $$\rightleftharpoons$$ [eIF5A-precursor]-deoxyhypusine + propane-1,3-diamine (overall reaction)
 * (1a) spermidine + NAD+ $$\rightleftharpoons$$ dehydrospermidine + NADH
 * (1b) dehydrospermidine + [enzyme]-lysine $$\rightleftharpoons$$ N-(4-aminobutylidene)-[enzyme]-lysine + propane-1,3-diamine
 * (1c) N-(4-aminobutylidene)-[enzyme]-lysine + [eIF5A-precursor]-lysine $$\rightleftharpoons$$ N-(4-aminobutylidene)-[eIF5A-precursor]-lysine + [enzyme]-lysine
 * (1d) N-(4-aminobutylidene)-[eIF5A-precursor]-lysine + NADH + H+ $$\rightleftharpoons$$ [eIF5A-precursor]-deoxyhypusine + NAD+

The eukaryotic initiation factor eIF5A contains a hypusine residue that is essential for activity.