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Identification of the major tRNA Phe binding domain in the tetrameric structure of cytoplasmic phenylalanyl‐tRNA synthetase from baker's yeast
Author(s) -
Fasiolo F.,
Sanni A.,
Potier S.,
Ebel J.P.,
Boulanger Y.
Publication year - 1989
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(89)80500-9
Subject(s) - transfer rna , biochemistry , tetramer , trypsin , protein subunit , peptide sequence , yeast , peptide , cleavage (geology) , amino acid , biology , chemistry , stereochemistry , enzyme , gene , rna , paleontology , fracture (geology)
Native cytoplasmic phenylalanyl‐tRNA synthetase from baker's yeast is a tetramer of the α 2 β 2 type. On mild tryptic cleavage it gives rise to a modified ∡ 2 β′ 2 form that has lost the tRNA Phe binding capacity but is still able to activate phenylalanine. In this paper are presented data concerning peptides released by this limited proteolytic conversion as well as those arising from exhaustive tryptic digestion of the truncated β′ subunit. Each purified peptide was unambiguously assigned to a unique stretch of the β subunit amino acid sequence that was recently determined via gene cloning and DNA sequencing. Together with earlier results from affinity labelling studies the present data show that the Lys 172—Ile 173 bond is the unique target of trypsin under mild conditions and that the N‐terminal domain of each β subunit (residues 1–172) contains the major tRNA Phe binding sites.