ABSTRACT
The possible curvature in the light-responsive element (LRE) of the plant gene which codes for the small subunit of ribulose-1,5-bisphosphate carboxylase has been derived from the nucleotide sequence of the LRE on the basis of a theoretical method previously developed in our research group. The oligonucleotides corresponding to regions of higher curvature in the profile, taking also into account biochemical data, have been synthesized and their electrophoretic mobilities have been measured after ligation. Retardation effects have been found, increasing with length of the multimers, in good agreement with theoretical prediction. These results suggest that the curvature of LRE could be the structural determinant in the control of rbcS-3A gene photoactivation.
Subject(s)
DNA/genetics , Genes , Oligonucleotide Probes , Plants/genetics , Ribulose-Bisphosphate Carboxylase/genetics , Base Sequence , Light , Macromolecular Substances , Molecular Sequence Data , Nucleic Acid Conformation , Plants/enzymology , ThermodynamicsABSTRACT
The density of the cytoplasmic DNA of two strains of "petite" mutants of yeast, obtained by treatment with acriflavin and with ultraviolet light, was examined in cesium chloride density-gradient centrifugation and in all cases appeared to be less than that of the wild type. A cytoplasmic respiratory-deficient strain, treated with additional acriflavin, can show a further shift of the position of the satellite band, always in the direction of reduction of density. Also, from the p(+) x p(-) cross, p(-) strains can be recovered in which the density of the satellite DNA is different from the density of the parent p(-) strain. This finding suggests the existence of recombination in cytoplasmic DNA moleciules.
