Anticodon-dependent aminoacylation of a noncognate tRNA with isoleucine, valine, and phenylalanine in vivo.
An assay based on the initiation of protein synthesis in Escherichia coli has been used to explore the role of the anticodon in tRNA identity in vivo. Mutations were introduced into the initiator tRNA to change the wild-type anticodon from CAU (methionine) to GAU (isoleucine), GAC (valine), and GAA (phenylalanine), where each derivative differs from the preceding by a single base change in the anticodon (underlined). These changes were sufficient to cause the mutant tRNAs to be aminoacylated by the corresponding aminoacyl-tRNA synthetases based on the amino acid inserted into protein from complementary initiation codons. Construction of additional single base anticodon variants (GUU, GGU, GCC, GUC, GCA, and UAA) showed that all three anticodon bases specify isoleucine and phenylalanine identity and that both the middle and the third anticodon bases are important for valine identity in vivo.
Pallanck
L
L
Department of Developmental Biology and Cancer, Albert Einstein College of Medicine, Bronx, NY 10461.
Schulman
L H
LH
D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism*; D000926:Anticodon; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics; D066298:In Vitro Techniques; D007532:Isoleucine / Q000378:metabolism*; D007533:Isoleucine-tRNA Ligase / Q000378:metabolism; D008969:Molecular Sequence Data; D010442:Peptide Chain Initiation, Translational; D010649:Phenylalanine / Q000378:metabolism*; D010652:Phenylalanine-tRNA Ligase / Q000378:metabolism; D012358:RNA, Transfer, Met / Q000378:metabolism*; D013379:Substrate Specificity; D014633:Valine / Q000378:metabolism*; D014637:Valine-tRNA Ligase / Q000378:metabolism
D000926:Anticodon; D012358:RNA, Transfer, Met; D007532:Isoleucine; D010649:Phenylalanine; D000604:Amino Acyl-tRNA Synthetases; D010652:Phenylalanine-tRNA Ligase; D007533:Isoleucine-tRNA Ligase; D014637:Valine-tRNA Ligase; D014633:Valine