Synapsis in phage Bxb1 integration: Selection mechanism for the correct pair of recombination sites
Synapsis in phage Bxb1 integration: Selection mechanism for the correct pair of recombination sites
复制标题
DOI：
10.1016/j.jmb.2005.03.043
复制
发表时间：
2005-06-03
影响因子：
5.6
通讯作者：
Hatfull, GF
中科院分区：
文献类型：
--
作者：
Ghosh, P;Pannunzio, NR;Hatfull, GF
通过位点特异性重组酶的重组是高度协同的过程，其需要正确的DNA底物对的突触。噬菌体编码的丝氨酸整合酶在包括转座子解离酶和DNA转化酶的丝氨酸重组酶家族中是不寻常的，因为它们利用两种简单但不同的DNA底物（attB和attP），并且不需要辅助位点、额外的蛋白质或DNA超螺旋。因此，突触必须完全由整合酶-DNA相互作用来指导。我们在这里表明，Bxb 1丝氨酸整合酶以二聚体形式与其两种DNA底物（attB、attP）和重组产物（attL、attR）以相似的亲和力结合。然而，突触只发生在attP和attB之间，而不是在其他九种可能的位点组合之间。Bxb 1整合酶结构域的结构，不寻常的DNA结合特性的整合酶，和突变体蛋白质的特征与改变的位点歧视，是一致的突触选择性来自DNA序列诱导的整合酶-DNA复合物的构象变化。(c)2005爱思唯尔有限公司保留所有权利。
Recombination by site-specific recombinases is a highly concerted process that requires synapsis of the correct pair of DNA substrates. Phage-encoded serine-integrases are unusual among the serine-recombinase family, which includes transposon resolvases and DNA invertases, in that they utilize two simple but different DNA substrates (attB and attP) and do not require accessory sites, additional proteins, or DNA supercoiling. Synapsis must therefore be directed solely by integrase-DNA interactions. We show here that the Bxb1 serine-integrase binds as a dimer to its two DNA substrates (attB, attP) and recombinant products (attL, attR) with similar affinities. However, synapsis occurs only between attP and attB, and not between any of the other nine possible site combinations. The Bxb1 integrase domain structure, the unusual DNA-binding properties of the integrase, and the characterization of a mutant protein with altered site-discrimination, are consistent with synaptic selectivity being derived from DNA sequence-induced changes in the conformations of integrase-DNA complexes. (c) 2005 Elsevier Ltd. All rights reserved.