Han S, Udvardy A, Schedl P
J Mol Biol. 1985 Aug 20;184(4):657-65. doi: 10.1016/0022-2836(85)90311-0.
We have examined the distribution of Neurospora crassa and S1 nuclease cleavage products in the chromatin of the hsp 83 heat shock gene from the Drosophila melanogaster cytogenetic locus 63 BC. Both of these nucleases generate double strand breaks in chromatin at specific sites close to the 5' end of the hsp 83 gene. With N. crassa nuclease we observe one major 5' fragment which is derived from nuclease cleavage in a DNA segment mapping approximately 120 base-pairs from the beginning of the transcription unit. With S1 nuclease we observe one major fragment which overlaps the transcription start site. In addition to the major hypersensitive sites at the beginning of the gene, the hsp 83 transcription unit is also sensitive to attack by these nucleases both before and after heat shock; however, the yield of cleavage products from within the gene is considerably greater after heat induction.
我们已经研究了粗糙脉孢菌（Neurospora crassa）和S1核酸酶切割产物在果蝇（Drosophila melanogaster）细胞遗传学位点63 BC的hsp 83热休克基因染色质中的分布。这两种核酸酶都在靠近hsp 83基因5'端的特定位点在染色质中产生双链断裂。使用粗糙脉孢菌核酸酶，我们观察到一个主要的5'片段，它来自于在距转录单元起始约120个碱基对的DNA片段中的核酸酶切割。使用S1核酸酶，我们观察到一个与转录起始位点重叠的主要片段。除了基因起始处的主要超敏位点外，hsp 83转录单元在热休克前后对这些核酸酶的攻击也很敏感；然而，热诱导后基因内切割产物的产量要高得多。
