The interaction of aminoacyl-tRNA and N-acylaminoacyl-tRNA with ribosomes and ribosomal subunits

Polypeptide Chain Initiation and Stepwise Elongation with Artemia Ribosomes and Factors

“…However, one must conclude from the data of Table 2 that there is no nucleoside triphosphate requirement. Other investigators noted the lack of GTP dependence for ribosomal binding of aminacyl-tRNA promoted by rat-liver supernatant factor (3,5,6) Table 3, show that the nonacylated compounds (MettRNAf and Phe-tRNA) are bound to a smaller extent than the N-acylated ones (fMet-tRNA and N-acetylPhe-tRNA), and the bound aminoacyl-tRNAs are less reactive with puromycin than the N-acylaminoacyl derivatives. It may also be seen in Table 3 that addition of GTP does not improve the reactivity of Met-tRNAf and Phe-tRNA.…”

“…In previous papers (1, 2), we reported on an initiation factor from postribosomal supernatants of embryos of the brine shrimp, Artemia salina, and its relation to factors from ratliver supernatant (3)(4)(5)(6) and rabbit-reticulocyte ribosomal washes (7) described by other investigators. The Artemia factor and the Escherichia coli initiation factor IF-2 are not interchangeable (2) but, as previously noted (1), the reaction promoted by Artemia factor, namely the AUG-dependent binding of fMet-tRNAf to eukaryotic 40S ribosomal subunits, shares certain properties with the analogous reaction catalyzed by IF-2 in bacterial systems: (a) it occurs on the small ribosomal subunit, (b) it is sensitive to edeine and aurintricarboxylic acid, and (c) the bound fMet-tRNAf is converted directly to fMet-puromycin upon addition of the large subunit.…”

“…Furthermore, the Artemia factor catalyzes, at low Mg2+ concentrations, not only the reported (1,3,5,6) binding of Phe-tRNA, but also that of Met-tRNAf to 40S subunits.…”

Polypeptide Chain Initiation in Eukaryotes: Functional Identity of Supernatant Factor from Various Sources

“…Factors that catalyze reactions similar to the one studied by us with Artemia have been reported in high-speed supernatants of wheat germ (2), rat liver (3)(4)(5), ascites cells (4), and yeast (6), as well as in washes of rabbit reticulocyte ribosomes with 0.5 M KCl [initiation factor M1 of Anderson and collaborators (7)]. In this paper, we report that the activity present in postribosomal supernatants of rat liver and in preparations of reticulocyte initiation factor M1, as well as an activity found in supernatant fractions from mouse L cells, is identical in many respects to that of the Artemia factor.…”

Μελετες Επι Της Πεπτιδυλοτρανσφερασης Σε Συστημα Απο Δικτυοερυθροκυτταρα Κουνελιου

“…β) Το διάγραμμα επαναδιάταξης των κλίσεων των ευθειών του DR-διαγράμ ματος (slope replot) έναντι των συγκεντρώσεων του αναστολέα (Ι). (Gasior et al 1971, Gavrilova et al 1976, Spirin 1986 (Miller and Schweet 1968, Jacobs-Lorena et al 1971, Nudel et al 1973, Schreier and Staehelin 1973, Dionne et al 1982 In 100 100-X'…”