期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1974
卷号：71
期号：8
页码：3199-3203
DOI：10.1073/pnas.71.8.3199
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：It is shown that initiation of translation involves several steps. (i) Binding of fMet-tRNAfMet to the bacterial 30S ribosomal subunit in the absence of messenger RNA, yielding a 34S complex. This binding is rapid and dependent on initiation factor 2 but not on initiation factor 3. (ii) Binding of messenger RNA to the 34S complex. This binding is slower and depends on initiation factor 3. If R17 RNA is used as messenger, the resulting complex sediments at 46 S. (iii) Joining of a 50S subunit to yield a complete initiation complex. Binding of fMet-tRNAfMet not only precedes, but is necessary for, correct binding of messenger RNA to ribosomes. Thus, initiator tRNA may play an active role in the selection of initiation sites in messenger RNA.
