[Extensive complementarity of the Shine-Dalgarno region and 3'-terminal sequence of 16S ribosomal RNA is inefficient for translation in vivo].
Translation initiation in Escherichia coli involves as a rule complementary interactions between a Shine-Dalgarno (SD) sequence upstream of the initiation codon and a highly conserved 3'-end sequence of 16S rRNA (anti-SD). The translation efficiency is believed to be directly affected by the affinity of the ribosome to the mRNA initiation region. Earlier, high-affinity RNA ligands to E. coli ribosomes were selected by the SELEX approach, with the ligands containing an extended SD-sequence well represented. In this work, we examined the ability of artificial ribosome binding sites (RBSs) containing such an extended (10-nt) SD-sequence (superSD) to drive translation in vivo, as well as its ability to form the translation initiation complex in vitro. Toe print experiments showed the formation of a ternary initiation complex on mRNA comprising superSD. Moreover, they proved the formation of an extended SD-duplex in the binary 30S-mRNA complex. Nevertheless, the superSD appeared to be inefficient in translation in vivo. We believe that the initiation complex involving a superSD-element is too stable to be functional; it may impede the transition from initiation to elongation, thus disrupting the transcription-translation coupling and inhibiting the formation of polysomes.
Komarova
A V
AV
Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, GSP Moscow, 117997 Russia.
Chufistova
L S
LS
Supina
E V
EV
Boni
I V
IV
D018387:Codon, Initiator / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D014176:Protein Biosynthesis; D026721:RNA 3' End Processing / Q000235:genetics*; D012336:RNA, Ribosomal, 16S / Q000235:genetics*
D018387:Codon, Initiator; D012336:RNA, Ribosomal, 16S