The site-specific recombination system of actinophage TG1
The site-specific recombination system of actinophage TG1
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DOI：
10.1111/j.1574-6968.2009.01683.x
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发表时间：
2009-08-01
影响因子：
2.1
通讯作者：
Takahashi, Hideo
中科院分区：
文献类型：
--
作者：
Morita, Kentaro;Yamamoto, Tomoyuki;Takahashi, Hideo
放线菌噬菌体TG 1通过整合在链霉菌菌株染色体上的独特位点形成稳定的溶原菌。噬菌体（attP（TG 1））和细菌（attB（TG 1））对TG 1的附着位点是从对阿维链霉菌TG 1溶原菌和非溶原菌的比较基因组研究中推导出来的。attB（TG 1）位于dapC基因（SAV 4517）的46 bp区域内，编码推定的N-琥珀酰二氨基庚二酸氨基转移酶。TG 1-溶原菌。然而，阿维菌素的生长不需要赖氨酸或二氨基庚二酸，这表明S.避免的做法需要重新考虑。使用attB（TG 1）序列的fasta程序对DNA数据库进行生物信息学调查，从不同的链霉菌基因组中提取了可能的整合位点，包括天蓝色链霉菌A3（2）和灰色链霉菌。编码推定的TG 1整合酶（int（TG 1））的基因位于attP（TG 1）位点附近。TG 1整合酶是由int（TG 1）基因推导的一个619个氨基酸组成的蛋白质，与C31整合酶具有很高的序列相似性，尤其是在N-末端催化区。相比之下，在C-末端区域的识别附着位点的关键序列相似性是中等或低。基于TG 1整合酶的位点特异性重组系统不仅在链霉菌株中有效，而且在异源大肠杆菌中也有效。
Actinophage TG1 forms stable lysogens by integrating at a unique site on chromosomes of Streptomyces strains. The phage (attP(TG1)) and bacterial (attB(TG1)) attachment sites for TG1 were deduced from comparative genomic studies on the TG1-lysogen and nonlysogen of Streptomyces avermitilis. The attB(TG1) was located within the 46-bp region in the dapC gene (SAV4517) encoding the putative N-succinyldiaminopimelate aminotransferase. TG1-lysogens of S. avermitilis, however, did not demand either lysine or diaminopimelate for growth, indicating that the dapC annotation of S. avermitilis requires reconsideration. A bioinformatic survey of DNA databases using the fasta program for the attB(TG1) sequence extracted possible integration sites from varied streptomycete genomes, including Streptomyces coelicolor A3(2) and Streptomyces griseus. The gene encoding the putative TG1 integrase (int(TG1)) was located adjacent to the attP(TG1) site. TG1 integrase deduced from the int(TG1) gene was a protein of 619 amino acids having a high sequence similarity to C31 integrase, especially at the N-terminal catalytic region. By contrast, sequence similarities at the C-terminal regions crucial for the recognition of attachment sites were moderate or low. The site-specific recombination systems based on TG1 integrase were shown to work efficiently not only in Streptomyces strains but also in heterologous Escherichia coli.