title: The structure of pre-messenger RNA and messenger RNA from erythroid cells.
abstract: Pre-mRNA fractions (greater than 45 S) were characterized by electron microscopy. High salt concentrations (0.2 M ammonium acetate, pH 8) yield linear molecules of different length (0.5--17 micrometer). In 10% of the molecules a compact-nonlinear contour (cn-contour) is detectable at one end. A significant enhancement of the number of cn-contour carrying molecules is observed after binding pre-mRNA to poly(U)-sepharose. The terminal cn-contour could be the depiction of a secondary and/or tertiary structure including the poly(A)-tail. 9 S globin mRNA appear in 80% with virtually the same cn-contour as detected in pre-mRNA molecules. After denaturing the mRNA in 80% formamide--4M urea in connection with heating to 90 degrees C from 10 min, a percentage of 77% of stretched, linear molecules results. This structural transformation is reversible when the denatured RNA is precipitated and redissolved in 0.2 M ammonium acetate. 73% of the stretched molecules are characterized by a mean length of 0.44 micrometer. This value is twice as high as commonly assumed for a globin mRNA chain.
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism*; D008854:Microscopy, Electron; D009691:Nucleic Acid Denaturation; D012333:RNA, Messenger / Q000097:blood*; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism
chemical_list: D012333:RNA, Messenger