Shell component of a type 1 encapsulin nanocompartment. Assembles into proteinaceous shells 23-24 nm in diameter with 2-2.5 nm thick walls. Cargo protein DyP (dye-decolorizing peroxidase) is targeted to the interior via its C-terminal extension; probably only 1 DyP hexamer is incorporated into each shell. Empty shells can be isolated in the absence of cargo. Homomultimeric (PubMed:7986050). This encapsulin nanocompartment is formed by 60 subunits; monomers form pentamers, which assemble to form hollow shells with several openings (By similarity). Belongs to the encapsulin family. Family 1 subfamily. Was originally thought to be a bacteriocin (PubMed:7986050); it has since been shown this is not the case (PubMed:19172747).