Involved in the biosynthesis of the chorismate, which leads to the biosynthesis of aromatic amino acids. Catalyzes the reversible NADPH linked reduction of 3-dehydroshikimate (DHSA) to yield shikimate (SA). It can also use NAD to oxidize shikimate. NADP(+) + shikimate = 3-dehydroshikimate + H(+) + NADPH kcat is 22.8 sec(-1) for dehydrogenase activity with shikimate (at pH 8 and at 25 degrees Celsius). kcat is 87 sec(-1) for dehydrogenase activity with NAD (at pH 8 and at 25 degrees Celsius). Metabolic intermediate biosynthesis; chorismate biosynthesis; chorismate from D-erythrose 4-phosphate and phosphoenolpyruvate: step 4/7. Monomer or homodimer. Belongs to the shikimate dehydrogenase family.