The Tsp45I restriction-modification system is plasmid-borne within its thermophilic host.
The Tsp45I restriction-modification system is plasmid-borne within its thermophilic host.
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Tsp45I 限制性修饰系统在其嗜热宿主内通过质粒传播。
DOI：
10.1016/s0378-1119(97)00457-5
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发表时间：
1997
期刊：
影响因子：
3.5
通讯作者：
S. Xu
中科院分区：
文献类型：
--
作者：
J. Wayne;M. Holden;S. Xu
温度菌YS45含有5.8(PTsp45s)和约12kb(PTsp45l)的两个小的隐含质粒。质粒pTsp45S已经完成测序，发现了三个重要的ORF。除了先前报道的嗜热性复制蛋白(Rep)外，pTsp45s还含有Tsp45I甲基转移酶(M.Tsp45I)和限制性内切酶(Tsp45I)两个基因。这两个融合基因(tsp45IM和tsp45IR)在XbaI位点的终止密码子上重叠4bp。M.Tsp45I(413aa，47.0 kDa，识别5‘-GTSAC-3’)与其他m6A-甲基转移酶高度同源，尤其是M.EcaI(识别5‘-GGTNACC-3’)。Tsp45I(332aa，37.4 kDa，切割5‘-↓GTSAC-3’)与M.Tsp45I或其他限制性内切酶不是同源的。重组Tsp45I在大肠杆菌中稳定产生，并在65℃下切割DNA，具有与天然酶相同的特异性。因此，嗜热性Tsp45I限制性内切酶修饰系统是在其天然宿主内携带的。
Thermus species YS45 harbors two small cryptic plasmids of 5.8 (pTsp45s) and approximately 12kb (pTsp45l). Plasmid pTsp45s has been entirely sequenced, revealing three significant ORFs. In addition to a previously reported thermophilic plasmid-encoded replication protein (Rep), pTsp45s contains two genes for the Tsp45I methyltransferase (M.Tsp45I) and restriction endonuclease (Tsp45I). These two converging genes (tsp45IM and tsp45IR) overlap by 4bp at their stop codons within an XbaI site. M.Tsp45I (413aa, 47.0kDa, recognizing 5′-GTSAC-3′) is highly homologous to other m6A-methyltransferases, especially M.EcaI (recognizing 5′-GGTNACC-3′). Tsp45I (332aa, 37.4kDa, cleaving 5′-↓GTSAC-3′) is not homologous to M.Tsp45I, or to other restriction endonucleases. Recombinant Tsp45I is stably produced in E. coli, and cleaves DNA at 65°C with the same specificity as the native enzyme. Therefore, the thermophilic Tsp45I restriction–modification system is plasmid-borne within its native host.
使用聚合酶链式反应构建 HinfI 限制性内切核酸酶的高效过量生产者克隆。
影响因子：
3.5
作者：
Skoglund,CM;Smith,HO;Chandrasegaran,S
通讯作者：
Chandrasegaran,S