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Cooperative Effects of Initiation Factors and fMet-tRNA in the Formation of the 40-S Initiation Complex.
- Source :
-
European Journal of Biochemistry . Jun76 Part 2, Vol. 66 Issue 1, p181-192. 12p. - Publication Year :
- 1976
-
Abstract
- In this paper the mode of action of IF-1 in 40-S initiation complex formation was studied with MS 2 RNA as messenger. Using initiation factors IF-2 and IF-3 labeled in vitro it appeared that IF-I did not influence the binding of these factors in the absence of fMet-tRNA. However, in the presence of fMet-tRNA it was found that the enhancement of the fMet-tRNA binding by IF-1 was accompanied with an equimolar increase in binding of IF-2. Moreover, it appeared that also in absence of IF-I, fMet-tRNA binding is coupled with an equimolar enhancement of the IF-2 binding, which suggests the existence of a preribosomal complex between IF-2 and fMet-tRNA. The apparent K,, values for both the binding of fMet-tRNA and IF-2 to 30-S subunits were determined and appeared to be equal, which makes a functioning of such a preribosomal complex in protein initiation very likely. The participation of GTP in this complex will be discussed. Functions of IF-I in dissociation and recycling of IF-2, described by others, and the stimulation on the 30-S subunit level might well be explained as pleiotropic effects of one basic action of IF-1, i.e. a conformational change of 30-S subunits. [ABSTRACT FROM AUTHOR]
- Subjects :
- *MESSENGER RNA
*RNA
*PROTEINS
*BIOMOLECULES
*BIOCHEMISTRY
Subjects
Details
- Language :
- English
- ISSN :
- 00142956
- Volume :
- 66
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- European Journal of Biochemistry
- Publication Type :
- Academic Journal
- Accession number :
- 13491765
- Full Text :
- https://doi.org/10.1111/j.1432-1033.1976.tb10438.x