Protein synthesis in rabbit reticulocytes: requirements for Met-tRNAf . 40S preinitiation complex formation with AUG-codon and physiological mRNAs.
Under standard conditions, in the presence of GTP, highly purified eIF-2 and Co-eIF-2 factor preparations efficiently stimulated AUG-codon dependent but not physiological mRNA-dependent Met-tRNAf binding to 40S ribosomes. Replacement of GTP by a nonhydrolyzable GTP analog, GMP-PNP, in the above system, gave significant stimulation of Met-tRNAf binding to 40S ribosomes dependent on physiological mRNAs. Lower but significant stimulation of Met-tRNAf binding to 40S ribosomes was also observed when GTP was used in the presence of nucleoside 5'-diphosphate kinase (NDK) and ATP. ATP alone in the absence of NDK had no significant effect. This is the first report on the formation of a stable Met-tRNAf . 40S initiation complex dependent on physiological mRNAs and the factor requirements for such complex formation.
D000818:Animals; D001798:Blood Proteins; D003062:Codon / Q000235:genetics*; D015852:Eukaryotic Initiation Factor-2; D005914:Globins / Q000235:genetics; D020662:Guanine Nucleotide Exchange Factors; D006160:Guanosine Triphosphate / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D007700:Kinetics; D010448:Peptide Initiation Factors / Q000097:blood*; D014176:Protein Biosynthesis / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics*; D012346:RNA, Transfer, Amino Acyl / Q000097:blood; D012358:RNA, Transfer, Met; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism*
D001798:Blood Proteins; D003062:Codon; D015852:Eukaryotic Initiation Factor-2; D020662:Guanine Nucleotide Exchange Factors; D010448:Peptide Initiation Factors; D012333:RNA, Messenger; D012346:RNA, Transfer, Amino Acyl; D012358:RNA, Transfer, Met; C024988:tRNA, formylmethionine-; D006165:Guanylyl Imidodiphosphate; D006160:Guanosine Triphosphate; D005914:Globins