Proteins L7 and L12 from the 50 S ribosomal subunit are required for polypeptide chain initiation in Escherichia coli. Ribosomes deficient in these proteins cannot participate in initiation factor IF 2 dependent hydrolysis of guanosine triphosphate (either 'coupled' or 'uncoupled' from initiation); activity can be restored by the addition of either L7 or L12. N Formyl methionyl transfer RNA binding to ribosomes is also impaired in the absence of L7 and L12. The results indicate that L7 or L12 is required for the catalytic function of IF 2 in binding N formyl methionyl transfer RNA to ribosomes. In each reaction tested, L7 and L12 are about equal in efficiency in restoring activity to depleted 50 S subunits. These results are discussed in the light of the current information on the role of these ribosomal proteins in other partial reactions or protein synthesis.
|Original language||English (US)|
|Number of pages||6|
|Journal||Journal of Biological Chemistry|
|State||Published - 1974|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology