Premium
The NH 2 ‐terminal cleavage of Escherichia coli translational initiation factor IF3
Author(s) -
Lammi Matilde,
Pon Cynthia L.,
Gualerzi Claudio O.
Publication year - 1987
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(87)80124-2
Subject(s) - cleavage (geology) , escherichia coli , chemistry , initiation factor , proteolysis , ribosome , peptide , biochemistry , protein subunit , biology , enzyme , rna , paleontology , fracture (geology) , gene
A short form of Escherichia coli translational initiation factor IF3, repeatedly found both in vivo and in vitro, lacking the positively charged N‐terminal hexapeptide has been produced by mild trypsinization. The properties of this short form of IF3 have been studied. Compared to the long native form of the factor, the shortened IF3 displays a markedly decreased thermal stability and affinity for the 30 S ribosomal sub‐unit, as well as a reduced biological activity in protein synthesis. Following the loss of the N‐terminal hexapeptide, a second peptide bond (Lys‐90Val‐91) becomes easily accessible to proteolytic attack suggesting that formation of the short IF3 may be the first step in the physiological degradation of the factor.