S-adenosyl-L-methionine-binding protein that acts as an inhibitor of mTORC1 signaling (PubMed:29123071). Acts as a sensor of S-adenosyl-L-methionine to signal methionine sufficiency to mTORC1 (PubMed:29123071). Probably also acts as a S-adenosyl-L-methionine-dependent methyltransferase. Belongs to the BMT2 family.