Involved in the biosynthesis of the chorismate, which leads to the biosynthesis of aromatic amino acids, and plays a key role in the quinate degradation pathway. Catalyzes the NAD(+)-dependent oxidation of both quinate and shikimate to 3-dehydroquinate and 3-dehydroshikimate, respectively. It can only use NAD. L-quinate + NAD(+) = 3-dehydroquinate + H(+) + NADH NAD(+) + shikimate = 3-dehydroshikimate + H(+) + NADH Metabolic intermediate biosynthesis; chorismate biosynthesis; chorismate from D-erythrose 4-phosphate and phosphoenolpyruvate: step 4/7. Aromatic compound metabolism; 3,4-dihydroxybenzoate biosynthesis; 3-dehydroquinate from D-quinate (NAD(+) route). Homodimer. Belongs to the shikimate dehydrogenase family.