The role of modified purine 64 in initiator/elongator discrimination of tRNA(iMet) from yeast and wheat germ.
The role of 2'-ribosylated adenosine 64 in tRNA(iMet) from yeast in initiation/elongation discrimination was investigated. As measured by in vitro translation in rabbit reticulocyte lysate, the specific removal of the 2'-ribosylphosphate at adenosine 64 via periodate oxidation allows tRNA(iMet) to read internal AUG codons of the globine messenger RNA. Yeast Met-tRNA(iMet) lacking the modification of nucleoside 64 forms ternary complexes with GTP and elongation factor Tu from Escherichia coli. The lack of modification at position 64 does not prevent tRNA(iMet) from participating in the initiation process of in vitro protein synthesis. Wheat germ tRNA(iMet) has a 2'-ribosylated guanosine at position 64. Removal of this modification from the wheat germ tRNA(iMet) enables it to read internal AUG codons of globine and tobacco mosaic virus messenger RNA in reticulocyte and wheat germ translation systems, respectively.
Laboratorium für Biochemie, Universität Bayreuth, FRG.
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D000241:Adenosine / Q000378:metabolism; D000818:Animals; D003062:Codon; D006151:Guanosine / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D046911:Macromolecular Substances; D010084:Oxidation-Reduction; D010441:Peptide Chain Elongation, Translational; D010442:Peptide Chain Initiation, Translational; D010444:Peptide Elongation Factor Tu / Q000378:metabolism; D014176:Protein Biosynthesis; D011687:Purines / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D012345:RNA, Transfer, Amino Acid-Specific / Q000378:metabolism*; D012358:RNA, Transfer, Met / Q000235:genetics / Q000378:metabolism*; D011817:Rabbits; D012156:Reticulocytes; D014027:Tobacco Mosaic Virus / Q000235:genetics; D014908:Triticum / Q000235:genetics*; D015003:Yeasts / Q000235:genetics*
D003062:Codon; D046911:Macromolecular Substances; D011687:Purines; D012333:RNA, Messenger; D012345:RNA, Transfer, Amino Acid-Specific; D012358:RNA, Transfer, Met; D006151:Guanosine; D006160:Guanosine Triphosphate; D010444:Peptide Elongation Factor Tu; D000241:Adenosine