[Structure of animal ribosomes. VI. Adynamic model of ribosome structure].
A dynamic model for the structure of ribosomes is developed using X-ray small-angle scattering data and electron micrographs of ribosomes and polysomes. The large subunit has the shape of a conical frustum, and has a groove at its flat side. The small subunit consists of two semiparticles which are connected by a molecular strand; it may assume two conformations: a prolate P conformation and an oblate O conformation. Translocation of the ribosome along the mRNA in the elongation process of protein synthesis is accomplished by cyclic conformation transitions P-O-P-O in combination with the linking and rupturing of bonds. This mechanism is called "rack and roll" mechanism.
D000818:Animals; D001665:Binding Sites; D008854:Microscopy, Electron; D011132:Polyribosomes / Q000648:ultrastructure; D014176:Protein Biosynthesis; D012333:RNA, Messenger; D012335:RNA, Ribosomal; D051381:Rats; D012270:Ribosomes / Q000648:ultrastructure*
D012333:RNA, Messenger; D012335:RNA, Ribosomal
Untersuchungen zur Struktur tierischer Ribosomen. VI. Ein dynamisches Modell der Ribosomenstruktur