共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Elongation by RNA polymerase II on chromatin templates requires topoisomerase activity 总被引:3,自引:2,他引:1 下载免费PDF全文
Mondal N Zhang Y Jonsson Z Dhar SK Kannapiran M Parvin JD 《Nucleic acids research》2003,31(17):5016-5024
3.
4.
5.
6.
7.
Bogoliubov DS 《Tsitologiia》2007,49(3):210-218
8.
Chromatin structure of a hyperactive secretory protein gene (in Balbiani ring 2) of Chironomus 总被引:5,自引:3,他引:2 下载免费PDF全文
R M Widmer R Lucchini M Lezzi B Meyer J M Sogo J E Edstr?m T Koller 《The EMBO journal》1984,3(7):1635-1641
We examined the chromatin structure of a Balbiani ring (secretory protein gene) in the salivary glands of Chironomus larvae in its hyperactive state after stimulation with pilocarpine. For the inactive state of the gene an established tissue culture cell line, not expressing the gene, was used. Electron microscopy showed an RNA polymerase density of approximately 38/microns. Micrococcal nuclease digestion of purified nuclei followed by DNA transfer and hybridization revealed a smear with no recognizable discrete DNA fragments. Without pilocarpine stimulation a faint nucleosomal repeat was superimposed upon the smear, and in tissue culture cells a clear nucleosomal repeat was revealed. The restriction enzyme XbaI, which has a 6-bp recognition sequence, cut the gene in the hyperactive chromatin state, but not in its inactive conformation. The combined results are best explained by the absence of most of the nucleosomes in this hyperactive RNA polymerase II transcribed gene. 相似文献
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
RNA polymerase B (or II) was localized by immunoelectron microscopy in ultrathin sections of polytene chromosomes isolated from larval salivary glands of Chironomus tentans. The enzyme was found at decondensed sites (puffs and interbands), whereas no detectable RNA polymerase B was present in condensed loci (bands). Within each of the large puffs the highest enzyme concentration was observed wherever the chromatin was in the most decondensed state. Otherwise the enzyme appeared homogeneously distributed within puffs and interbands. This immunoelectron microscopic study, along with the recently published immunofluorescent and autoradiographic analysis of isolated Chironomus chromosomes (Sass, 1982) unequivocally demonstrates that RNA polymerase B is present in most, if not all interbands. 相似文献
19.