In vitro codon-reading specificities of unmodified tRNA molecules with different anticodons on the sequence background of Escherichia coli tRNASer
Takai, K.; Takaku, H.; Yokoyama, S.
Biochemical and Biophysical Research Communications 257(3): 662-667
1999
ISSN/ISBN: 0006-291X PMID: 10208840 Document Number: 508503
The codon-reading properties of wobble-position variants of the unmodified form of Escherichia coli tRNA1Ser (the UGA anticodon) were measured in a cell-free translation system. Two variants, with the AGA and CGA anticodons, each exclusively read a single codon, UCU and UCG, respectively. The only case of efficient wobbling occurred with the variant with the GGA anticodon, which reads the UCU codon in addition to the UCC codon. Surprisingly, this wobble reading is more efficient than the Watson-Crick reading by the variant with the AGA anticodon. Furthermore, we prepared tRNA variants with, AA, UC, and CU, instead of GA, in the second and third positions and measured their relative efficiencies in the reading of codons starting with UU, GA, and AG, respectively. The specificity concerning the wobble position is essentially the same as that in the case of the colons starting with UC.