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Formation of the central pseudoknot in 16S rRNA is essential for initiation of translation.
Author(s) -
Brink M.F.,
Verbeet M.P.,
Boer H.A.
Publication year - 1993
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1993.tb06076.x
Subject(s) - pseudoknot , biology , library science , genetics , gene , base sequence , computer science
The postulated central pseudoknot formed by regions 9–13/21–25 and 17–19/916–918 of 16S rRNA of Escherichia coli is phylogenetically conserved in prokaryotic as well eukaryotic species. This pseudoknot is located at the center of the secondary structure of the 16S rRNA and connects the three major domains of this molecule. We have introduced mutations into this pseudoknot by changing the base‐paired residues C18 and G917, and the effect of such mutations on the ribosomal activity was studied in vivo, using a ‘specialized’ ribosome system. As compared with ribosomes having the wild‐type pseudoknot, the translational activity of ribosomes containing an A, G or U residue at position 18 was dramatically reduced, while the activity of mutant ribosomes having complementary bases at positions 18 and 917 was at the wild‐type level. The reduced translational activity of those mutants that are incapable of forming a pseudoknot was caused by their inability to form 70S ribosomal complexes. These results demonstrate that the potential formation of a central pseudoknot in 16S rRNA with any base‐paired residues at positions 18 and 917 is essential to complete the initiation process.