Abstract
Mg2+ was shown to affect the conformation of rRNA over the range of 0.03-1.2M-KCl. The species studies were Escherichia coli S-rRNA and L-rRNA (the RNA moieties of the smaller and larger subribosomal particles respectively) and rabbits S-rRNA and L-rRNA. 2. The addition of Mg2+ to rRNA in reconstitution buffer (0.35M-KCl0.01M-Tris/HCl, pH7.2) at 20° C let to an increase in bihelical secondary structure through the formation of additional (mainly A-U) base-pairs (e.g. an additional approx. 58 A-U base-pairs per molecule of E. coli S-rRNA as judged by u.v. difference spectrophotometry…