May function as a riboflavin storage protein that binds and sequesters riboflavin, thereby protecting cells against undesirable reactions mediated by free riboflavin. Protects bound flavin against light damage; flavin fluorescence is rapidly quenched by interaction with Trp-39. Homododecamer; 12 subunits assemble to form a hollow sphere. Belongs to the dodecin family. Dodecin family members from different organisms have non-identical ligand binding specificity.