Mycobacteriophage Bxb1 integrates into the Mycobacterium smegmatis groEL1 gene
Mycobacteriophage Bxb1 integrates into the Mycobacterium smegmatis groEL1 gene
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DOI：
10.1046/j.1365-2958.2003.03723.x
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发表时间：
2003-10-01
影响因子：
3.6
通讯作者：
Hatfull, GF
中科院分区：
文献类型：
--
作者：
Kim, AI;Ghosh, P;Hatfull, GF
分枝杆菌噬菌体 Bxb1 是耻垢分枝杆菌的温带噬菌体，可形成稳定的溶原菌，其中 Bxb1 基因组整合到宿主染色体中。 Bxb1 编码大丝氨酸重组酶家族的整合酶，催化 Bxb1 基因组的整合和切除。我们在此表明，Bxb1 整合到位于 groEL1 基因 3' 端的染色体 attB 位点，从而整合导致 C 端 21 个氨基酸残基的改变。含有 Bxb1 整合酶基因和侧翼 DNA 序列的整合能力强的质粒载体通过 attB 处的整合有效转化耻垢分枝杆菌。 Bxb1 整合重组体稳定且与 L5 整合载体完全兼容。链交换发生在 attB 中存在的 8 bp 共同核心序列内以及位于噬菌体整合酶基因紧上游的 attP 位点内。建立用于 Bxb1 整合的明确体外系统表明，无需高能辅因子、二价金属、DNA 超螺旋或其他蛋白质即可有效发生重组。
Mycobacteriophage Bxb1 is a temperate phage of Mycobacterium smegmatis and forms stable lysogens in which the Bxb1 genome is integrated into the host chromosome. Bxb1 encodes an integrase of the large serine recombinase family that catalyses integration and excision of the Bxb1 genome. We show here that Bxb1 integrates into a chromosomal attB site located within the 3' end of the groEL1 gene such that integration results in alteration of the C-terminal 21 amino acid residues. An integration-proficient plasmid vector containing the Bxb1 integrase gene and flanking DNA sequences efficiently transforms M. smegmatis via integration at attB. Bxb1-integrated recombinants are stable and fully compatible with L5 integration vectors. Strand exchange occurs within an 8 bp common core sequence present in attB and within an attP site situated immediately upstream of the phage integrase gene. Establishment of a defined in vitro system for Bxb1 integration shows that recombination occurs efficiently without requirement for high-energy cofactors, divalent metals, DNA supercoiling or additional proteins.