Catalyzes the oxidative ring opening of 3-hydroxyanthranilate to 2-amino-3-carboxymuconate semialdehyde, which spontaneously cyclizes to quinolinate. 3-hydroxyanthranilate + O2 = (2Z,4Z)-2-amino-3-carboxymuconate 6-semialdehyde Cofactor biosynthesis; NAD(+) biosynthesis; quinolinate from L-kynurenine: step 3/3. Monomer. Belongs to the 3-HAO family.