Involved in the biosynthesis of pyridine alkaloid natural products, leading mainly to the production of anabasine, anatabine, nicotine and nornicotine, effective deterrents against herbivores with antiparasitic and pesticide properties (neurotoxins); nornicotine serves as the precursor in the synthesis of the carcinogen compound N'-nitrosonornicotine (NNN) (PubMed:23953973, PubMed:31276744). Catalyzes the condensation of iminoaspartate with dihydroxyacetone phosphate to form quinolinate (By similarity). dihydroxyacetone phosphate + iminosuccinate = H(+) + 2 H2O + phosphate + quinolinate Binds 1 [4Fe-4S] cluster per subunit. Alkaloid biosynthesis; nicotine biosynthesis. Cofactor biosynthesis; NAD(+) biosynthesis; quinolinate from iminoaspartate: step 1/1. Homodimer. Belongs to the quinolinate synthase family. Type 1 subfamily.