title: Initiation of protein synthesis in yeast: binding of Met-tRNAi.
abstract: Conditions for the binding of Met-tRNAi to 40 s ribosomal subunits and to proteins isolated out of the yeast ribosomal KCl wash were investigated. Sucrose density gradient experiments revealed that binding of Met-tRNAi to 40 s ribosomal subunits was catalyzed in a AUG and GTP dependent reaction. Binding of Met-tRNAi to proteins of the ribosomal KCl wash as assayed by the Millipore filter technique was found to be independent of AUG, GTP and 40 s ribosomal subunits. Additions of GTP yielded only slight stimulation, whereas Mg2+ caused dissociation of complexes. It was concluded that these reactions were most likely catalyzed by initiation factor eIF-2 although stimulation by GTP did not occur.
mesh_terms: D015852:Eukaryotic Initiation Factor-2; D005656:Fungal Proteins / Q000096:biosynthesis*; D006160:Guanosine Triphosphate / Q000378:metabolism; D007700:Kinetics; D009994:Osmolar Concentration; D010442:Peptide Chain Initiation, Translational; D010448:Peptide Initiation Factors / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*
chemical_list: D015852:Eukaryotic Initiation Factor-2; D005656:Fungal Proteins; D010448:Peptide Initiation Factors; D011506:Proteins; D012346:RNA, Transfer, Amino Acyl; C026464:tRNA(m)(Met), methionine-; D006160:Guanosine Triphosphate