Single-strand DNA translation initiation step analyzed by Isothermal Titration Calorimetry.
Is single-strand DNA translatable? Since the 60s, the question still remains whether or not DNA could be directly translated into protein. Some discrepancies in the results were reported about functional translation of single-strand DNA but all results converged on a similar behavior of RNA and ssDNA in the initiation step. Isothermal Titration Calorimetry method was used to determine thermodynamic constants of interaction between single-strand DNA and S30 extract of Escherichia coli. Our results showed that the binding was not affected by the nature of the template tested and the dissociation constants were in the same range when ssDNA (K(d)=3.62+/-2.1 x 10(-8)M) or the RNA corresponding sequence (K(d)=2.7+/-0.82 x 10(-8) M) bearing SD/ATG sequences were used. The binding specificity was confirmed by antibiotic interferences which block the initiation complex formation. These results suggest that the limiting step in translation of ssDNA is the elongation process.
Damian
Luminita
L
CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, F-31077 Toulouse, France. luminitadamian@microcal.eu.com
Marty-Detraves
Claire
C
Winterhalter
Mathias
M
Fournier
Didier
D
Paquereau
Laurent
L
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001312:Aurintricarboxylic Acid / Q000494:pharmacology; D002151:Calorimetry / Q000379:methods*; D004277:DNA, Single-Stranded / Q000378:metabolism*; D010441:Peptide Chain Elongation, Translational; D010442:Peptide Chain Initiation, Translational / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism
D000900:Anti-Bacterial Agents; D004277:DNA, Single-Stranded; D012333:RNA, Messenger; D001312:Aurintricarboxylic Acid