The crystal structure of the immature holo-enzyme of homoserine dehydrogenase complexed with NADP and 1,4-butandiol from the hyperthermophilic archaeon Sulfurisphaera tokodaii.
This domain adopts a Rossmann NAD binding fold. The C-terminal domain of homoserine dehydrogenase contributes a single helix to this structural domain, which is not included in the Pfam model.