A gene for a Class II DNA photolyase from Oryza sativa:: cloning of the cDNA by dilution-amplification
A gene for a Class II DNA photolyase from Oryza sativa:: cloning of the cDNA by dilution-amplification
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DOI：
10.1007/s00438-003-0856-9
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发表时间：
2003-07-01
影响因子：
3.1
通讯作者：
Yamamoto, K
中科院分区：
文献类型：
--
作者：
Hirouchi, T;Nakajima, S;Yamamoto, K
紫外线辐射诱导 DNA 中两类光产物的形成 - 环丁烷嘧啶二聚体 (CPD) 和嘧啶 [6-4] 嘧啶酮光产物（6-4 产物）。许多生物体会产生称为光裂合酶的酶，这种酶特异性地与这些病变结合，并通过 UV-A/蓝光依赖性机制将其分解，从而逆转损伤。这些光裂合酶对 CPD 或 6-4 产品具有特异性。两类光裂合酶（I 类和 11 类）可修复 CPD。编码具有体外 11 类 CPD 光裂合酶活性的蛋白质的基因已从拟南芥、黄瓜和莱茵衣藻等多种植物中克隆出来。我们在此报道从水稻 (Oryza sativa) 中分离出该基因的同源物，该基因是根据序列相似性和基于 PCR 的稀释扩增进行克隆的。 cDNA 包含非常富含 GC (75%) 的 5' 区域，而 3' 部分的 GC 含量为 50%。该基因在大肠杆菌中表达时编码具有 CPD 光裂合酶活性的蛋白质。 CPD光裂合酶基因编码至少两种类型的mRNA，由外显子5的选择性剪接形成。其中一种mRNA编码506个氨基酸残基的ORF，而另一种预计编码364个氨基酸残基。这两种 RNA 在水稻细胞中的含量大致相等。
Ultraviolet radiation induces the formation of two classes of photoproducts in DNA-the cyclobutane pyrimidine dimer (CPD) and the pyrimidine [6-4] pyrimidone photoproduct (6-4 product). Many organisms produce enzymes, termed photolyases, which specifically bind to these lesions and split them via a UV-A/blue light-dependent mechanism, thereby reversing the damage. These photolyases are specific for either CPDs or 6-4 products. Two classes of photolyases (class I and class 11) repair CPDs. A gene that encodes a protein with class 11 CPD photolyase activity in vitro has been cloned from several plants including Arabidopsis thaliana, Cucumis sativus and Chlamydomonas reinhardtii. We report here the isolation of a homolog of this gene from rice (Oryza sativa), which was cloned on the basis of sequence similarity and PCR-based dilution-amplification. The cDNA comprises a very GC-rich (75%) 5' region, while the 3' portion has a GC content of 50%. This gene encodes a protein with CPD photolyase activity when expressed in E. coli. The CPD photolyase gene encodes at least two types of mRNA, formed by alternative splicing of exon 5. One of the mRNAs encodes an ORF for 506 amino acid residues, while the other is predicted to code for 364 amino acid residues. The two RNAs occur in about equal amounts in O. sativa cells.