| - | Translation initiation is a major determinant of the overall expression, level of a gene. The translation of functionally active protein requires, the messenger RNA to be positioned on the ribosome such that the, start/initiation codon will be read first and in the correct frame. Little, is known about the molecular basis for the interaction of mRNA with the, ribosome at different states of translation. Recent crystal structures of, the ribosomal subunits, the empty 70S ribosome and the 70S ribosome, containing functional ligands have provided information about the general, organization of the ribosome and its functional centres. Here we compare, the X-ray structures of eight ribosome complexes modelling the translation, initiation, post-initiation and elongation states. In the initiation and, post-initiation complexes, the presence of the Shine-Dalgarno (SD) duplex, causes strong anchoring of the 5'-end of mRNA onto the platform of the 30S, subunit, with numerous interactions between mRNA and the ribosome., Conversely, the 5' end of the 'elongator' mRNA lacking SD interactions is, flexible, suggesting a different exit path for mRNA during elongation., After the initiation of translation, but while an SD interaction is still, present, mRNA moves in the 3'-->5' direction with simultaneous clockwise, rotation and lengthening of the SD duplex, bringing it into contact with, ribosomal protein S2.
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| - | Structural basis for messenger RNA movement on the ribosome., Yusupova G, Jenner L, Rees B, Moras D, Yusupov M, Nature. 2006 Nov 16;444(7117):391-4. Epub 2006 Oct 18. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17051149 17051149]
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