A 2.5 kb polypyrimidine tract in the PKD1 gene contains at least 23 H-DNA-forming sequences.
A 2.5 kb polypyrimidine tract in the PKD1 gene contains at least 23 H-DNA-forming sequences.
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PKD1 基因中的 2.5 kb 聚嘧啶段包含至少 23 个 H-DNA 形成序列。
DOI：
10.1089/mcg.1996.1.317
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Landes,GM
中科院分区：
文献类型：
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作者：
VanRaay,TJ;Burn,TC;Connors,TD;Petry,LR;Germino,GG;Klinger,KW;Landes,GM
富含嘧啶的元件（PyRE）存在于PKD 1基因的第21内含子中，对确定该基因的一级结构构成了重大障碍。只有富含CT链的嵌套单链噬菌体模板的循环测序才能获得完整和准确的序列数据。在富含GA的链上的类似尝试没有成功。一级结构显示3 kb的第21内含子含有2.5kb的PyRE，其有义链为97%的C + T。PKD 1 PyRE似乎没有多态性的基础上的RFLP分析的DNA从6个无关的个人消化9种不同的限制性内切酶。这是迄今为止测序的最大的嘧啶段，是以前鉴定的嘧啶段的两倍多，并且与其他多嘧啶段几乎没有同源性。对该PyRE的额外分析揭示了存在23个镜像重复，其中茎长度至少为10个核苷酸。PKD 1 PyRE中的23个H-DNA形成序列超过了已完全测序的157个人类基因中发现的22个累积序列。镜像重复赋予PKD 1基因的这一区域在适当条件下形成H-DNA或三链体结构的可能性很大。基于对其他真核基因中发现的PyRE的研究，PKD 1 PyRE可能在调节PKD 1表达方面发挥作用，其形成扩展三链体结构的潜力可能解释了PKD 1基因座中观察到的一些不稳定性。
A pyrimidine-rich element (PyRE), present in the 21st intron of thePKD1gene, posed a significant obstacle in determining the primary structure of the gene. Only cycle sequencing of nested, single-stranded phage templates of the CT-rich strand enabled complete and accurate sequence data. Similar attempts on the GA-rich strand were unsuccessful. The resulting primary structure showed the 3 kb 21st intron to contain a 2.5 kb PyRE, whose sensestrand is 97% C + T. The PKD1 PyRE does not appear to be polymorphic based on RFLP analysis of DNA from 6 unrelated individuals digested with 9 different restriction enzymes. This is the largest pyrimidine tract sequenced to date, being over twice as large as those previously identified and shows little homology to other polypyrimidine tracts. Additional analysis of this PyRE revealed the presence of 23 mirror repeats with stem lengths of at least 10 nucleotides. The 23 H-DNA-forming sequences in the PKD1 PyRE exceed the cumulative total of 22 found in 157 human genes that have been completely sequenced. The mirror repeats confer this region of thePKD1gene with a strong probability of forming H-DNA or triplex structures under appropriate conditions. Based on studies with PyRE found in other eukaryotic genes, thePKD1PyRE may play a role in regulating PKD1 expression, and its potential for forming an extended triplex structure may explain some of the observed instability in thePKD1locus.