The conformation of a large RNA fragment from the E.coli ribosomal 16S-RNA. An X-ray and neutron small-angle scattering study

A large 12S RNA fragment which constitutes the 5' two-thirds of 16S-RNA from the E. coli 30S subunit has been investigated by small-angle X-ray and neutron scattering. The results indicate that in reconstitution buffer the 12S-RNA fragment has a molecular weight of 270,000 +/- 20,000 and a radius of gyration of 7.1 nm. The scattering data are compatible with the RNA being folded into two major domains with the shapes of two adjacent, quite similar cylinders.