The variety of intraspecific misacylations carried out by isoleucyl transfer ribonucleic acid synthetase of Escherichia coli.

摘要: Abstract The variety of tRNAs (Escherichia coli) misisoleucylated by isoleucyl-tRNA synthetase in normal and mixed solvents is examined. method employs microscale amino acid radioanalysis, used to detect release cognate acids from which have been previously protected periodate misisoleucylation. In the presence unresolved acceptor highly purified simultaneously misacylates several E. coli B species addition those studied (tRNAPhe (Yarus, M. (1972) Biochemistry 11, 2352) tRNAMet (Mertes, M., Peters, M.A., Mahoney, W., Yarus, J. Mol. Biol. 71, 671)). There a tendency for chemically similar be more easily misacylated. Some reactions are detectable both (20% methanol). contrast tRNAPhe tRNAMet, misacylation some not responsive methanol. Thus, intercognate barriers lowered solvents, not. This suggests that distinguishes at least two molecular mechanisms. Comparison these data with experiments other laboratories enables one descry "family" tRNAs, defined as set most misacylated aminoacyl-tRNA synthetases hydrophobic acids.