Sequence and positional requirements for DNA sites in a Mu transpososome
Sequence and positional requirements for DNA sites in a Mu transpososome
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DOI：
10.1074/jbc.m110342200
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发表时间：
2002-03-08
影响因子：
4.8
通讯作者：
Baker, TA
中科院分区：
文献类型：
--
作者：
Goldhaber-Gordon, I;Early, MH;Baker, TA
Transposition of bacteriophage Mu uses two DNA cleavage sites and six transposase recognition sites, with each recognition site divided into two half-sites. The recognition sites can activate transposition of non-Mu DNA sequences if a complete set of Mu sequences is not available. We have analyzed 18 sequences from a non-Mu DNA molecule, selected in a functional assay for the ability to be transposed by MuA transposase. These sequences are remarkably diverse. Nonetheless, when viewed as a group they resemble a Mu DNA end, with a cleavage site and a single recognition site. Analysis of these "pseudo-Mu ends" indicates that most positions in the cleavage and recognition sites contribute sequence-specific information that helps drive transposition, though only the strongest contributors are apparent from mutagenesis data. The sequence analysis also suggests variability in the alignment of recognition half-sites. Transposition assays of specifically designed DNA substrates support the conclusion that the transposition machinery is flexible enough to permit variability in half-site spacing and also perhaps variability in the placement of the recognition site with respect to the cleavage site. This variability causes only local perturbations in the protein-DNA complex, as indicated by experiments in which altered and unaltered DNA substrates are paired.
