Premium
Proteolysis of Bacillus stearothermophilus IF2 and specific protection by fMet‐tRNA
Author(s) -
Severini Manuela,
Choli Theodora,
La Teana Anna,
Gualerzi Claudio O.
Publication year - 1992
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(92)80543-p
Subject(s) - proteolysis , transfer rna , gtp' , biochemistry , protease , eukaryotic translation , chemistry , c terminus , initiation factor , amino acid , translation (biology) , biology , ribosome , enzyme , rna , gene , messenger rna
Translation initiation factor IF2 from Bacillus steaiothermophilus (741 amino acids, M r 82,043) was subjected to trypsinolysis alone or in the presence of fMet‐tRNA. The initiator tRNA was found to protect very efficiently the Arg 308 ‐Ala 309 bond within the GTP binding site of IF2 and, more weakly, three bonds (Lys 146 ‐Gln 147 , Lys 154 ‐Glu 155 and Arg 519 ‐Ser 520 ). The first two are located at the border between the non‐conserved, dispensable (for translation) N‐terminal portion and the conserved G‐domain of the protein, the third is located at the border between the G‐ and C‐domains. Since IF2 is known to interact with fMet‐tRNA through its protease‐resistant C‐ (carboxyl terminus) domain, the observed protection suggests that, upon binding or fMet‐tRNA, long‐distance tertiary interactions between the IF2 domains may take place.