Purification and characterization of three elongation factors, EF-1 alpha, EF-1 beta gamma, and EF-2, from wheat germ.
Three elongation factors, EF-1 alpha, EF-1 beta gamma and EF-2, have been isolated from wheat germ. EF-1 alpha and EF-2 are single polypeptides with molecular weights of approximately 52,000 and 102,000, respectively. The most highly purified preparations of EF-1 beta gamma contain four polypeptides with molecular weights of approximately 48,000, 46,000 and 36,000, 34,000. EF-1 alpha supports poly(U)-directed binding of Phe-tRNA to wheat germ ribosomes and catalyzes the hydrolysis of GTP in the presence of ribosomes, poly(U), and Phe-tRNA. EF-2 catalyzes the hydrolysis of GTP in the presence of ribosomes alone and is ADP-ribosylated by diphtheria toxin to the extent of 0.95 mol of ADP-ribose/mol of EF-2. EF-1 beta gamma decreases the amount of EF-1 alpha required for polyphenylalanine synthesis about 20-fold. EF-1 beta gamma enhances the ability to EF-1 alpha to support the binding of Phe-tRNA to the ribosomes and enhances the GTPase activity of EF-1 alpha. Wheat germ EF-1 alpha, EF-1 beta gamma, and EF-2 support polyphenylalanine synthesis on rabbit reticulocyte ribosomes as well as on yeast ribosomes.
D007700:Kinetics; D008970:Molecular Weight; D010441:Peptide Chain Elongation, Translational; D020648:Peptide Elongation Factor 1; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors / Q000302:isolation & purification* / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D014908:Triticum / Q000378:metabolism
D020648:Peptide Elongation Factor 1; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors; D012346:RNA, Transfer, Amino Acyl