ATP cross-linked to Escherichia coli single-strand DNA-binding protein can be utilized by the catalytic center of primase as initiating nucleotide for primer RNA synthesis on phage G4oric template.
ATP cross-linked to Escherichia coli single-strand DNA-binding protein can be utilized by the catalytic center of primase as initiating nucleotide for primer RNA synthesis on phage G4oric template.
复制标题
与大肠杆菌单链 DNA 结合蛋白交联的 ATP 可以被引物酶的催化中心用作在噬菌体 G4oric 模板上合成引物 RNA 的起始核苷酸。
DOI：
10.1021/bi972455f
复制
发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Sun,W
中科院分区：
文献类型：
--
作者：
Godson,GN;Mustaev,AA;Sun,W
本文报道了在大肠杆菌引物酶催化下，以噬菌体G_4 oric为模板合成引物RNA（pRNA）过程中，噬菌体单链DNA结合蛋白（SSB）的作用。使用一组具有连接到不同长度“臂”上的5' γ-磷酸的反应基团的ATP引发底物，我们已经证明，在引发酶/SSB/G4 oric pRNA合成复合物中，与引发酶和SSB交联的ATP可以同样用作pRNA合成的起始核苷酸。SSB表面与引发基质的α-磷之间的距离估计小于7 μ m。与引发酶和SSB交联的ATP可以在其他NTP的存在下进一步延长，得到长度高达12个核苷酸的共价连接的pRNA的几乎相同的模式。因此，引发酶和SSB中可用于pRNA合成的具有交联ATP的区域相对于pRNA合成的活性中心以类似的方式排列。与SSB共价连接的pRNA被定位，映射在Met 48和Trp 88之间。这一观察结果提出了SSB可能在该系统中pRNA合成的起始中发挥积极作用的可能性。
We report a new observation of the role ofEscherichiacolisingle-strand DNA binding protein (SSB) in synthesis of primer RNA (pRNA) catalyzed byE.coliprimase on the SSB-coated phage G4oric template. Using a set of ATP priming substrates with reactive groups attached to the 5‘ γ-phosphate on different length “arms”, we have demonstrated that, in the primase/SSB/G4oric pRNA synthesis complex, ATP cross-linked to both primase and SSB could be equally utilized as initiating nucleotide for pRNA synthesis. The distance between SSB surface and α-phosphorus of the priming substrate was estimated to be less than 7 Å. ATP cross-linked to primase and SSB can be further elongated in the presence of other NTPs, giving almost identical patterns of covalently attached pRNAs of up to 12 nucleotides in length. The regions of primase and SSB with cross-linked ATP that can be used for pRNA synthesis are, therefore, arranged in a similar way relative to the active center of pRNA synthesis. The pRNA covalently linked to SSB was localized, mapping between Met48 and Trp88. This observation raises the possibility that SSB may play an active role in the initiation of pRNA synthesis in this system.