InterPro domain: IPR036982

Eukaryotic initiation factor 5A (eIF-5A), now considered to be an elongation factor (see IPR001884 ), contains an unusual amino acid, hypusine [N epsilon-(4-aminobutyl-2-hydroxy)lysine]. The first step in the post-translational formation of hypusine is catalysed by the enzyme deoxyhypusine synthase (DS, 2.5.1.46 ). The enzyme catalyses the following reaction:

Spermidine + [eIF-5A]-lysine = 1,3-diaminopropane + [eIF-5A]-deoxyhypusine

The modified version of eIF-5A, and DS, are required for eukaryotic cell proliferation [ 1 ]. The structure is known for this enzyme in complex with its NAD ⁺ cofactor, it is a tetramer of four identical subunits arranged with 222 symmetry where each subunit contains a Rossmann fold [ 2 ].

1. Crystal structure of the NAD complex of human deoxyhypusine synthase: an enzyme with a ball-and-chain mechanism for blocking the active site. Structure 6, 23-32