Structure and RNA content of the prosomes

Abstract Duck erythroblast, prosomes were analysed by small angle neutron scattering (SANS), dynamic light scattering and (cryo-)electron microscopy. A molecular weight of ≈ 720,000 ± 50,000, a radius of gyration of 64 ± 2 A and a hydrodynamic radius of ≈ 86 A were obtained. Electron micrographs show a hollow cylinder-like particle with a diameter of 120 A, n height of 170 A and a diameter of 40 A for the cavity, built of four discs, the two outer ones being more pronounced than those in the center. Results from SANS indicate less then 5% of RNA in the purified prosomes, but nuclease protection assays confirm its presence.