Open AccessInitial Dipeptide Formation in Hemoglobin Biosynthesis
Author(s) -
Ronald G. Crystal,
David A. Shafritz,
Philip M. Prichard,
W. French Anderson
Publication year - 1971
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.68.8.1810
Subject(s) - dipeptide , reticulocyte , transfer rna , ribosome , valine , protein biosynthesis , biosynthesis , hemoglobin , biochemistry , ribosomal rna , stereochemistry , peptide bond , biology , translation (biology) , peptide , chemistry , amino acid , messenger rna , rna , enzyme , gene
Initiation factors M1 + M2 from reticulocyte ribosomes bind Met-tRNAF to rabbit reticulocyte ribosomes containing endogenous hemoglobin mRNA. The initial binding of Met-tRNAF appears to be to the small ribosomal subunit. The Met-tRNAF is able to participate in what is presumed to be the first peptide bond in the formation of hemoglobin, namely the synthesis of a methionyl-valine dipeptide. The formation of this methionyl-valine dipeptide requires Met-tRNAF , initiation factors M1 , M2 , and M3 , as well as Val-tRNA and T1 . No synthesis of methionyl-valine dipeptide takes place if Met-tRNAF is replaced by Met-tRNAM , or if initiation factor M3 is omitted. Thus, Met-tRNAF appears to be the initiator tRNA for hemoglobin biosynthesis and M3 , although required for the synthesis of the first peptide bond of hemoglobin, does not appear to be necessary, under the experimental conditions studied, for Met-tRNAF binding.