tRNA hopping: effects of mutant tRNAs.
Movement of tRNA and mRNA through the ribosome is coupled. However, selection for suppression of a -1 frameshift mutation in Escherichia coli has yielded a class of mutant tRNAs that can violate this mechanism and "hop" or disengage from their cognate codons and re-pair downstream in the mRNA. Previously described tRNA mutants of this class included those with insertions in the anticodon of tRNA(Val)1. This report describes further tRNA(Val)1 alterations that enhance hopping; these include a novel insertion in the anticodon loop, base substitutions in the anticodon stem and a base deletion in the variable loop. These results indicate that several different features of a tRNA are important for maintaining stable codon-anticodon interactions and coupled movement of tRNA and mRNA during the elongation phase of protein synthesis.
School of Biological Sciences, University of Missouri-Kansas City, 5007 Rockhill Road, Kansas City, MO 64110, USA. oconnormi@umkc.edu
Michael
M
O'Connor
D000926:Anticodon / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D001693:Biological Transport, Active; D003062:Codon / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D016368:Frameshift Mutation; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009154:Mutation; D009690:Nucleic Acid Conformation; D020871:RNA Stability; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012343:RNA, Transfer / Q000235:genetics* / Q000378:metabolism*; D012366:RNA, Transfer, Val / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D017384:Sequence Deletion; D013489:Suppression, Genetic
D000926:Anticodon; D003062:Codon; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012366:RNA, Transfer, Val; D012343:RNA, Transfer