Formation of a 22S mRNA X rRNA X protein complex during translation of globin messenger RNA.
Poly(A)-rich RNA was isolated from rabbit reticulocyte polyribosomes by affinity chromatography on oligo(dT)-cellulose and fractionated in sucrose gradients under non-denaturing conditions. Most of the translatable RNA sedimented in sucrose gradients both as free 9S mRNA and as a 22S complex containing 18S ribosomal RNA and a protein of Mr 66 000. The complex was characterized by identification of the translation products. Experiments with both labelled globin mRNA and Mr-66 000 protein indicate that the complex is not an artefact, but rather that it is formed during the initiation of protein synthesis. The Mr-66 000 protein appears to be a component of the 48S pre-initiation complex and recycles before 80S complex formation.
D000818:Animals; D002499:Centrifugation, Density Gradient; D005914:Globins / Q000235:genetics*; D046911:Macromolecular Substances; D008970:Molecular Weight; D010442:Peptide Chain Initiation, Translational; D011061:Poly A / Q000032:analysis; D011132:Polyribosomes / Q000032:analysis; D014176:Protein Biosynthesis; D012313:RNA / Q000032:analysis; D012333:RNA, Messenger / Q000378:metabolism*; D012335:RNA, Ribosomal / Q000378:metabolism*; D011817:Rabbits; D012156:Reticulocytes / Q000032:analysis; D012269:Ribosomal Proteins / Q000378:metabolism*
D046911:Macromolecular Substances; D012333:RNA, Messenger; D012335:RNA, Ribosomal; D012269:Ribosomal Proteins; D011061:Poly A; D012313:RNA; D005914:Globins