Conserved amino acid motifs from the novel Piv/MooV family of transposases and site-specific recombinases are required for catalysis of DNA inversion by Piv.
Conserved amino acid motifs from the novel Piv/MooV family of transposases and site-specific recombinases are required for catalysis of DNA inversion by Piv.
复制标题
Piv 催化 DNA 倒转需要来自新型 Piv/MooV 转座酶家族和位点特异性重组酶的保守氨基酸基序。
DOI：
10.1046/j.1365-2958.2001.02276.x
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发表时间：
2001
影响因子：
3.6
通讯作者：
Karls,AC
中科院分区：
文献类型：
--
作者：
Tobiason,DM;Buchner,JM;Thiel,WH;Gernert,KM;Karls,AC
Piv是一种来自裂孔莫拉菌的位点特异性转化酶，与IS110/ is492插入元件家族的转座酶具有氨基酸同源性。通过诱变Piv中每个基序中完全保守的氨基酸，研究了定义这个新转座酶家族和位点特异性重组酶（Piv/MooV家族）的保守氨基酸基序的功能。所有在保守残基上发生改变的Piv突变体在体内转化时都存在缺陷。不可逆转的DNA片段，但能够与Piv DNA识别序列结合。虽然Piv/MooV重组酶的一级氨基酸序列不包含保守的DDE基序，而DDE基序定义了逆转录病毒整合酶/转座酶（IN/Tnps）家族，但预测的Piv二级结构元件与已确定晶体结构的IN/Tnps的二级结构元件非常一致。基于这些序列的Piv分子模型预测，在Piv/MooV家族中保守为E或D的E59与保守的D9和D101残基形成催化袋。对Piv E59G的分析证实了E59在催化转化中的作用。这些结果表明Piv和相关的IS110/ is492转座酶通过涉及催化DED或DDD基序的共同机制介导DNA重组。
Piv, a site‐specific invertase fromMoraxella lacunata, exhibits amino acid homology with the transposases of the IS110/IS492family of insertion elements. The functions of conserved amino acid motifs that define this novel family of both transposases and site‐specific recombinases (Piv/MooV family) were examined by mutagenesis of fully conserved amino acids within each motif in Piv. All Piv mutants altered in conserved residues were defective forin vivoinversion of theM. lacunatainvertible DNA segment, but competent forin vivobinding to Piv DNA recognition sequences. Although the primary amino acid sequences of the Piv/MooV recombinases do not contain a conserved DDE motif, which defines the retroviral integrase/transposase (IN/Tnps) family, the predicted secondary structural elements of Piv align well with those of the IN/Tnps for which crystal structures have been determined. Molecular modelling of Piv based on these alignments predicts that E59, conserved as either E or D in the Piv/MooV family, forms a catalytic pocket with the conserved D9 and D101 residues. Analysis of Piv E59G confirms a role for E59 in catalysis of inversion. These results suggest that Piv and the related IS110/IS492transposases mediate DNA recombination by a common mechanism involving a catalytic DED or DDD motif.