Open AccessAmino acid sequence of mammalian elongation factor 2 deduced from the cDNA sequence: homology with GTP-binding proteins.
Author(s) -
Kenji Kohno,
Tsuyoshi Uchida,
Hiroaki Ohkubo,
Shigetada Nakanishi,
Tohru Nakanishi,
Toshikazu Fukui,
Eiko Ohtsuka,
Morio Ikehara,
Yoshio Okada
Publication year - 1986
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.83.14.4978
Subject(s) - elongation factor , biology , gtp' , peptide sequence , biochemistry , ef tu , complementary dna , amino acid , eukaryotic translation elongation factor 1 alpha 1 , gtpase , nucleic acid sequence , microbiology and biotechnology , ribosome , dna , rna , gene , enzyme
Complementary DNA clones, pHEW1 and pRE2, coding for hamster and rat polypeptide chain elongation factor 2 (EF-2), respectively, were isolated and sequenced. It was shown that the cDNA insert in pHEW1 contains a 2574-base-pair open reading frame coding for an 857-amino acid polypeptide with Mr 95,192, excluding the initiation methionine. Comparative studies of sequence homology among EF-2 and several GTP-binding proteins show that five regions in the amino-terminal position of EF-2, corresponding to about 160 amino acids, show homology with GTP-binding proteins, including protein synthesis elongation and initiation factors, mammalian ras proteins, and transducin. The carboxyl-terminal half of EF-2 contains several regions that have 34-75% homology with bacterial elongation factor G. These results suggest that the amino-terminal region of EF-2 participates in the GTP-binding and GTPase activity whereas the carboxyl-terminal region interacts with ribosomes. Finally, the sequence provides direct evidence that diphthamide (2-[3-carboxy-amido-3-(trimethylammonio)propyl]histidine), the site of ADP-ribosylation by diphtheria toxin, is produced by post-translational modification of a histidine residue in the primary translational product.