Showing papers on "Nucleic acid secondary structure published in 1972"
TL;DR: With this assay, Sindbis virus RNA, phage f2 RNA, and polyuridylate have been found to have different amounts of secondary structure.
Abstract: A chromatographic procedure is described which can discriminate among single-stranded ribonucleic acid (RNA) molecules in solution on the basis of the extent of their secondary structure. The assay is effected through chromatography at different temperatures with columns of cellulose CF-11. When Sindbis virus RNA is chromatographed in this system, the ratio of the amounts of RNA eluting in the single-stranded peak to those eluting in the double-stranded peak increases at higher temperatures, presumably a measure of the relative amounts of Sindbis virus RNA secondary structure at different temperatures. With this assay, Sindbis virus RNA, phage f2 RNA, and polyuridylate have been found to have different amounts of secondary structure.
18 citations
TL;DR: It is shown that selection has not reduced useless protein synthesis by minimizing the number of out of register AUG's or maximizing the number in of register terminating codons in messenger RNA.
Abstract: The RNA sequences in the region of the coat protein gene of MS2/R17 phage, of the maturation protein gene ofQβ and of a 6s-RNA transcribed from a presumptive gene ofλ were examined. All but five of the 61 amino acid codons are present in these messages and although there is some evidence of a bias in the frequency of utilization of the codons, there is little evidence to suggest that any codons may be forbidden. It is shown that selection has not reduced useless protein synthesis by minimizing the number of out of register AUG's or maximizing the number of out of register terminating codons in messenger RNA. Secondary structures of the RNA's were formulated using a modification of the diagonal method of Tinocoet al. (1971). Of the 12 AUG triplets considered in the sequences only one is a primary attachment site for ribosomes and it is the only one of the 12 that appears in end loops with none of the bases paired. A thirteenth AUG triplet appears at the beginning of the 6s-RNAλ gene. Its occurrence in an end loop free of base pairing suggests that this is a ribosome binding site. It is speculated (1), that transcriptase may recognize its binding site on the DNA by a procedure that is in part the analogue of the protein synthetase recognizing its binding-initiation site, namely that as the DNA strands are separated, a secondary structure forms in the sense strand with a CAT in the end loop; (2), that reverse transcriptase might be useful as a means of keeping multiple copies of a gene identical if it were to correct the sense strand DNA in a DNA-RNA hybrid; and (3), that processing of RNA in the intercistronic region normally occurs in the same manner as translation, namely, moving the RNA through, three nucleotides at a time.
17 citations
TL;DR: The study of the kinetics of DNA renaturation has yielded much information about the organization of the DNA in eukaryotes into families of nucleotide sequences, and it has been shown that the 800-fold redundant ribosomal RNA genes of Xenopus laevis form a family of closely related base sequence.
Abstract: The study of the kinetics of DNA renaturation has yielded much information about the organization of the DNA in eukaryotes into families of nucleotide sequences (Britten and Kohne, 1967, 1968; Wetmur and Davidson, 1968). With a few exceptions the entire assemblage of families of related base sequences of any one organism is treated as a single body of DNA. It is possible to study the renaturation behaviour of a family of genes coding for a specific RNA of genes within the total genomic DNA, but such experiments are tedious to carry out and so fax have required a combination of hydroxylapatite fractionation of the renaturing DNA (Flamm et al., 1969) and subsequent identification of the specific DNA segments by RNA/DNA hybridization. By this indirect approach it has been shown, for example, that the 800-fold redundant ribosomal RNA genes of Xenopus laevis form a family of closely related base sequence (Grunstein, unpublished) Similarly, after preselection of ribosomal DNA complements from bacteria by RNA/DNA hybridization the renaturation kinetics for these DNA segments indicate that bacterial ribosomal cistrons are similar in base sequence (Kohne, 1968).
6 citations