Open AccessRelease of Polypeptide Chain Initiation Factor IF-2 During Initiation Complex Formation
Author(s) -
Arthur H. Lockwood,
Probir Kumar Sarkar,
Umadas Maitra
Publication year - 1972
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.69.12.3602
Subject(s) - gtp' , initiation factor , ribosome , eukaryotic initiation factor , chemistry , eif2 , eukaryotic translation , polypeptide chain , complex formation , biochemistry , translation (biology) , biophysics , microbiology and biotechnology , stereochemistry , biology , rna , messenger rna , enzyme , gene , inorganic chemistry
Polypeptide chain initiation factor IF-2 binds to 30S ribosomal subunits. This binding is enhanced by IF-1 and IF-3. During GTP-dependent formation of a 70S initiation complex, IF-2 is released from the ribosome. During 70S initiation complex formation dependent on the methylene analogue of GTP, GMPPCH2 P, IF-2 is not released, but remains bound to the 70S ribosome. This result suggests that IF-2 release requires GTP hydrolysis. In agreement with this presumed requirement, IF-2 functions catalytically with GTP, but stoichiometrically with GMPPCH2 P, in bringing about 70S initiation complex formation.