[{"from": "human", "value": "Provide a brief overview of this molecule. [C][C][=C][Branch1][=N][C][=Branch1][C][=O][N][C][=Branch1][C][=O][N][Ring1][Branch2][/C][=C][/C][=Branch1][C][=O][C]"}, {"from": "gpt", "value": "The molecule is a nucleobase analogue that is uracil substituted with a methyl group at position 6 and a (1E)-3-oxobut-1-en-1-yl group at position 5; one of 20 modifications to the potent microbial riboflavin-based metabolite antigen 5-(2-oxopropylideneamino)-6-D-ribityl aminouracil (5-OP-RU), an activator of mucosal-associated invariant T (MAIT) cells when presented by the MR1 protein (reported in MED:32123373). It has a role as an epitope. It is a nucleobase analogue and a pyrimidone. It is functionally related to a uracil."}]