Ribosome Initiation and the Mode of Action of Neomycin in the Direct Translation of Single-Stranded fd DNA (original) (raw)

1. Mark S. Bretscher
2. Medical Research Council Laboratory of Molecular Biology, University Postgraduate Medical School, Cambridge, England

Excerpt

Single stranded DNA does not serve as a messenger in a normal E. coli extract, demonstrating that some part of the protein-synthesizing machinery can distinguish between otherwise similar polyribonucleotides and polydeoxyribonucleotides. We may ask which components are responsible for recognizing this difference, or at which step in protein synthesis a DNA messenger is nonfunctional. Furthermore, an analog of a messenger RNA (mRNA) might be useful for certain experiments, and I should like first to describe one such experiment.

It has been shown by Morgan, Wells, and Khorana (1967) that a repeating polydeoxyribonucleotide, such as poly d(TG), could serve as a messenger in binding N-formyl-methionyl-transfer RNA (F-met-tRNA) to ribosomes. This binding requires the presence of both the initiation factors and GTP. This observation enables one to ask whether a circular single-stranded DNA could also serve as a messenger in binding F-met-tRNA to ribosomes. The reason for wishing to answer this question...