Idiosyncratic tuning of tRNAs to achieve uniform ribosome binding.
The binding of seven tRNA anticodons to their complementary codons on Escherichia coli ribosomes was substantially impaired, as compared with the binding of their natural tRNAs, when they were transplanted into tRNA(2)(Ala). An analysis of chimeras composed of tRNA(2)(Ala) and various amounts of either tRNA(3)(Gly) or tRNA(2)(Arg) indicates that the presence of the parental 32-38 nucleotide pair is sufficient to restore ribosome binding of the transplanted anticodons. Furthermore, mutagenesis of tRNA(2)(Ala) showed that its highly conserved A32-U38 pair serves to weaken ribosome affinity. We propose that this negative binding determinant is used to offset the very tight codon-anticodon interaction of tRNA(2)(Ala). This suggests that each tRNA sequence has coevolved with its anticodon to tune ribosome affinity to a value that is the same for all tRNAs.
Olejniczak
Mikołaj
M
Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA.
Dale
Taraka
T
Fahlman
Richard P
RP
Uhlenbeck
Olke C
OC
D000926:Anticodon / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D004926:Escherichia coli; D007700:Kinetics; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009690:Nucleic Acid Conformation; D012343:RNA, Transfer / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012344:RNA, Transfer, Ala / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism*; D013379:Substrate Specificity
D000926:Anticodon; D012344:RNA, Transfer, Ala; D012343:RNA, Transfer