CHARACTERIZATION AND IMMUNOLOGICAL IDENTIFICATION OF CDNA CLONES ENCODING 2 HUMAN DNA TOPOISOMERASE-II ISOZYMES
CHARACTERIZATION AND IMMUNOLOGICAL IDENTIFICATION OF CDNA CLONES ENCODING 2 HUMAN DNA TOPOISOMERASE-II ISOZYMES
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DOI：
10.1073/pnas.86.23.9431
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发表时间：
1989-12-01
影响因子：
11.1
通讯作者：
MIRABELLI, CK
中科院分区：
文献类型：
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作者：
CHUNG, TDY;DRAKE, FH;MIRABELLI, CK
对从人Raji-HN2cDNA文库中获得的几个DNA拓扑异构酶II(Topo II；EC 5.99.1.3)部分cDNA克隆进行了测序，发现了两类核苷酸序列。第一类中的一个成员SP1与前面描述的人HeLa细胞Topo II基因的一个内部片段相同。第二类成员SP11与HeLa Topo II的前三分之二序列有广泛的核苷酸(75%)和预测的多肽(92%)相似之处。每一类cDNA都与几个人类细胞系基因组DNA的独特的、不重叠的限制性内切酶片段杂交。合成的针对每一cDNA类的24聚体寡核苷酸探针与6.5kb碱基的mRNAs杂交；此外，针对一类的探针的杂交不会被另一类的特异性探针所阻断。针对合成的SP1编码的十二肽的抗体特异性地识别Topo II的170 kDa形式，而针对相应的SP11编码的十二肽或第二个独特的SP11编码的十三肽的抗体选择性地识别Topo II的180 kDa形式。这些数据为两种Topo II同工酶提供了遗传和免疫化学证据。
Several DNA topoisomerase II (Topo II; EC 5.99.1.3) partial cDNA clones obtained from a human Raji-HN2 cDNA library were sequenced and two classes of nucleotide sequences were found. One member of the first class, SP1, was identical to an internal fragment of human HeLa cell Topo II cDNA described earlier. A member of the second class, SP11, shared extensive nucleotide (75%) and predicted peptide (92%) sequence similarities with the first two-thirds of HeLa Topo II. Each class of cDNAs hybridized to unique, nonoverlapping restriction enzyme fragments of genomic DNA from several human cell lines. Synthetic 24-mer oligonucleotide probes specific for each cDNA class hybridized to 6.5-kilobase mRNAs; furthermore, hybridization of probe specific for one class was not blocked by probe specific for the other. Antibodies raised against a synthetic SP1-encoded dodecapeptide specifically recognized the 170-kDa form of Topo II, while antibodies raised against the corresponding SP11-encoded dodecapeptide, or a second unique Sp11-encoded tridecapeptide, selectively recognized the 180-kDa form of Topo II. These data provide genetic and immunochemical evidence for two Topo II isozymes.