Binding constants in the formation of mammalian protein synthesis initiation complexes and the role of mRNA.
The findings of Parkhurst et al. (Biochemistry 33, 15168-15177:1994) that a 10-mer oligoribonucleotide containing the AUG triplet enhances the binding of the eIF-2 x Met-tRNAi complex to the 40S ribosomal subunit are questioned on the basis of a re-evaluation of their calculations. It is not possible to conclude, as they did, that addition of the AUG-containing oligonucleotide produces an exceptionally large increase (as judged by the magnitude of the coupling free energy) in the binding of the eIF-2 x Met-tRNAi complex to the 40S subunit, or that their results are more consistent with internal initiation than with the scanning initiation model.
Manchester
K L
KL
Department of Biochemistry, University of the Witwatersrand, Johannesburg, South Africa.
D000818:Animals; D001483:Base Sequence; D015852:Eukaryotic Initiation Factor-2 / Q000378:metabolism*; D007700:Kinetics; D008322:Mammals; D008956:Models, Chemical; D009843:Oligoribonucleotides; D010442:Peptide Chain Initiation, Translational; D012333:RNA, Messenger / Q000378:metabolism*; D012358:RNA, Transfer, Met / Q000378:metabolism*; D015203:Reproducibility of Results; D012270:Ribosomes / Q000378:metabolism; D012984:Software; D013816:Thermodynamics
D015852:Eukaryotic Initiation Factor-2; D009843:Oligoribonucleotides; D012333:RNA, Messenger; D012358:RNA, Transfer, Met