CONTRIBUTION OF POLYADENYLIC-ACID SEQUENCES TO THE MAINTENANCE OF SECONDARY STRUCTURE OF GLOBIN MESSENGER-RNA

Purified rabbit hemoglobin mRNA (HbmRNA) has been characterized by cell-free translation in vitro and by denaturing (glyoxal) gel electrophoresis. Enzymatic deadenylation yields shorter molecules, susceptible of translation but unable to serve as a template for reverse transcriptase. Comparison between thermal denaturation parameters of intact and deadenylated HbmRNA in phosphate buffer alone before and after reaction with formaldehyde (900 × 10 min) and in phosphate buffered 4M guanidinium chloride indicates a highly ordered secondary structure, 10% of which is given by single stranded base stacking, in intact HbmRNA. Deadenylated HbmRNA displays very little single stranded base stacking, suggesting that most of this contribution to the overall structure of intact HbmRNA is given by its poly (A) sequence. © 1979.