X-ray structures of transfer RNAs (tRNAs) bound to the whole ribosome do not fully explain the mechanism of translation. The cause of the failure seems to come mainly from a high Mg2+ ion concentration compared to tha...X-ray structures of transfer RNAs (tRNAs) bound to the whole ribosome do not fully explain the mechanism of translation. The cause of the failure seems to come mainly from a high Mg2+ ion concentration compared to that in the living cells. There exists a wide range of nucleotide sequence conservation in tRNA and ribosomal RNAs (rRNAs) of small and large subunits as well as sequence complementarities, that seems to explain how high accuracy in translation can be achieved at the decoding site. Conformational transition between U33-folded and U33-extended forms of anticodon loops of tRNAs and G-C pair formation and disruption between C1399 and G1504 of 16S rRNA, etc. play the central role in explaining why E-site tRNA can automatically be expelled when an aminoacyl-tRNA at the A site turns out to be cognate.展开更多
文摘X-ray structures of transfer RNAs (tRNAs) bound to the whole ribosome do not fully explain the mechanism of translation. The cause of the failure seems to come mainly from a high Mg2+ ion concentration compared to that in the living cells. There exists a wide range of nucleotide sequence conservation in tRNA and ribosomal RNAs (rRNAs) of small and large subunits as well as sequence complementarities, that seems to explain how high accuracy in translation can be achieved at the decoding site. Conformational transition between U33-folded and U33-extended forms of anticodon loops of tRNAs and G-C pair formation and disruption between C1399 and G1504 of 16S rRNA, etc. play the central role in explaining why E-site tRNA can automatically be expelled when an aminoacyl-tRNA at the A site turns out to be cognate.
