Sequences in attB that affect the ability of phiC31 integrase to synapse and to activate DNA cleavage.
Sequences in attB that affect the ability of phiC31 integrase to synapse and to activate DNA cleavage.
复制标题
ATTB中影响PHIC31积分酶突触和激活DNA裂解的能力的序列。
DOI：
10.1093/nar/gkm206
复制
发表时间：
2007
影响因子：
14.9
通讯作者：
Smith, Margaret C M
中科院分区：
文献类型：
--
作者：
Gupta, Milind;Till, Rob;Smith, Margaret C M
噬菌体整合酶是噬菌体基因组与宿主染色体重组以建立或退出溶原性状态所必需的。C31整合酶是位点特异性重组酶的丝氨酸重组酶家族的成员。在没有任何辅助因子的情况下，整合酶是单向的，催化噬菌体和宿主附着位点之间的整合反应，attP × attB，以产生杂合位点attL和attR。这种方向性的基础是由于attP和attB位点的选择性突触。在这里，我们表明attB突变可以在不同阶段阻断整合反应。在交叉位点远端位置的突变通过使与attP的突触不稳定来抑制重组，而不显著影响DNA结合亲和力。这些数据与整合酶在与attB结合时采用允许与attP突触的特定构象的提议一致。其他attB突变体的变化接近交叉位点，能够形成一个稳定的突触，但裂解的基板被阻止。这些突变体表明存在导致DNA切割激活的突触后DNA识别事件。
Phage integrases are required for recombination of the phage genome with the host chromosome either to establish or exit from the lysogenic state. ϕC31 integrase is a member of the serine recombinase family of site-specific recombinases. In the absence of any accessory factors integrase is unidirectional, catalysing the integration reaction between the phage and host attachment sites, attP × attB to generate the hybrid sites, attL and attR. The basis for this directionality is due to selective synapsis of attP and attB sites. Here we show that mutations in attB can block the integration reaction at different stages. Mutations at positions distal to the crossover site inhibit recombination by destabilizing the synapse with attP without significantly affecting DNA-binding affinity. These data are consistent with the proposal that integrase adopts a specific conformation on binding to attB that permits synapsis with attP. Other attB mutants with changes close to the crossover site are able to form a stable synapse but cleavage of the substrates is prevented. These mutants indicate that there is a post-synaptic DNA recognition event that results in activation of DNA cleavage.