For ten points, identify this amino acid with an indole functional group.
One pathway to synthesize this involves the condensation of anthranilate with phosphoribosylpyrophosphate. Cytotoxic T lymphocyte-associated antigen 4 regulates the cytokine dependent catabolism of this molecule in dendritic cells, and consumption of large amounts of this chemical may result in eosinophilia-myalgia syndrome. Its namesake synthase exhibits substrate channeling by passing the intermediate through a tunnel before it reacts with serine. Deficiencies of a certain neurotransmitter can be caused by fructose malabsorbtion in the intestines as it lowers the level of this amino acid in the blood. That neurotransmitter, serotonin, is synthesized from this amino acid as are melatonin and niacin. For ten points, identify this amino acid with an indole functional group.
One pathway to synthesize this involves the condensation of anthranilate with phosphoribosylpyrophosphate.
{tryptophan}