title: An effect of codon context on the mistranslation of UGU codons in vitro.
abstract: Effects of codon context on nonsense codon suppression may act either through release factor recognition of termination codons or aminoacyl-tRNA selection by the ribosome. The latter hypothesis has been studied by comparing misreading by Escherichia coli UGA suppressor tryptophan tRNA of UGU (cysteine) codons in two synthetic polymers, poly(U-G) and poly( U5 , G), which differ in sequence around the UGU codons. In vitro translation of these polymers in a cell-free system from E. coli yielded selection errors of 4 X 10(-3) and 1.75 X 10(-2) for UGU codons in poly(U-G) and poly( U5 , G), respectively. This difference suggests that codon context may significantly affect misincorporation of amino acids into protein.
mesh_terms: D003062:Codon; D003545:Cysteine / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D009154:Mutation; D011068:Poly G / Q000235:genetics; D011072:Poly U / Q000235:genetics; D014176:Protein Biosynthesis; D012333:RNA, Messenger; D012346:RNA, Transfer, Amino Acyl / Q000235:genetics; D014633:Valine / Q000235:genetics
chemical_list: D003062:Codon; D012333:RNA, Messenger; D012346:RNA, Transfer, Amino Acyl; D011068:Poly G; C023795:poly(U-G); D011072:Poly U; D014633:Valine; D003545:Cysteine