Ribosomal subunits from Tetrahymena pyriformis. Isolation and properties of active 40-S and 60-S subunits.
Tetrahymena pyriformis ribosomal subunits were obtained by incubation of post-mitochondrial supernatant in the presence of 0.2 mM GTP and 0.1 mM puromycin for 45 min at 28 degrees C, followed by sucrose density gradient centrifugation. Isolated 40-S subunits were able to reassociate in vitro in the presence of 5 mM MgCl2 and 50 mM KCl and to perform poly(U)-dependent protein synthesis. The 60-S subunit carries the peptidyl transferase activity. The number of proteins in T. pyriformis ribosomal subunits was determined by two-dimensional polyacrylamide gel electrophoresis. The 40-S subunit contains 30 different protein species (including two acidic proteins). The 60-S subunit contains 35 different protein species (including two acidic proteins). The proteins were numbered following the system of Kaltschmidt and Wittmann.
D000818:Animals; D008970:Molecular Weight; D010458:Peptidyl Transferases / Q000378:metabolism; D011072:Poly U; D014176:Protein Biosynthesis; D012269:Ribosomal Proteins / Q000096:biosynthesis*; D012270:Ribosomes / Q000378:metabolism*; D013045:Species Specificity; D013769:Tetrahymena pyriformis / Q000378:metabolism*
D012269:Ribosomal Proteins; D011072:Poly U; D010458:Peptidyl Transferases