DNase I hypersensitive sites of the chromatin for Drosophila melanogaster ribosomal protein 49 gene.

By using an indirect end-labelling technique for mapping, five DNase I hypersensitive sites have been located in Drosophila melanogaster chromatin at the 5'-end of the gene coding for ribosomal protein 49. These sites typically span about 100-600 base pairs and are approximately the length of a nucleosome apart (center to center distance ca 245 bp). This is the first analysis of the chromatin structure of a constitutive house-keeping gene. The results support the hypothesis that the presence of such a DNase 1 hypersensitive site in chromatin is necessary for transcription in vivo. The presence of such sites may reflect some local changes in the conformation of the chromatin in the presumptive regulatory region.