Open AccessTranslational discrimination between the four RNAs of alfalfa mosaic virus
Author(s) -
GODEFROYCOLBURN Thérèse,
THIVENT Christine,
PINCK Lothaire
Publication year - 1985
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.0014-2956.1985.00541.x
Subject(s) - rna , reticulocyte , nuclease , biology , nucleic acid , translation (biology) , wheat germ , messenger rna , microbiology and biotechnology , genetics , biochemistry , dna , gene
In an attempt to relate the translational characteristics of alfalfa mosaic virus (AIMV) RNAs to their structure [Ravelonandro et al. (1983) Nucleic Acids Res. 11 , 2815–2826; Gehrke et al. (1983) Biochemistry 22 , 5157–5164] we measured the relative affinities (discrimination ratios) of these RNAs for the initiation complex, in the wheat germ extract and in the nuclease‐treated reticulocyte lysate, using a competition method designed by Brendler et al. [(1981) J. Biol. Chem. 256 , 11747–11754]. As a prerequistite of this study we ascertained that the molecular mass distribution of the translation products was independent of RNA concentration in both translation systems. In the wheat germ extract the discrimination ratios are very similar for two strains of AIMV (S and B) which diffet mainly by the presence (strain S) or absence (strain B) of a stable 5′‐proximal hairpin. Hence this structure has no bearing on discrimination. Taking the affinity of RNA 3 as reference, the following orders of magnitude are found for the affinities of the different RNAs in the wheat germ: RNA 3, 1.0; RNA 1, 10; RNA 2, 60; RNA 4, 150. In the reticulocyte lysate the discrimination ratios are not significantly different from the wheat germ. Thus it seems that the mechanism of discrimination is essentially the same in the two translation systems, despite a difference in rate‐limitation.