Structural basis for recognition of AT-rich DNA by unrelated xenogeneic silencing proteins
- 影响因子：
0.0
- 发表刊物：
Proc Natl Acad Sci U S A
- 摘要：
H-NS and Lsr2 are nucleoid-associated proteins from Gram-negative bacteria and Mycobacteria, respectively, that play an important role in the silencing of horizontally acquired foreign DNA that is more AT-rich than the resident genome. Despite the fact that Lsr2 and H-NS proteins are dissimilar in sequence and structure, they serve apparently similar functions and can functionally complement one another. The mechanism by which these xenogeneic silencers selectively target AT-rich DNA has been enigmatic. We performed high-resolution protein binding microarray analysis to simultaneously assess the binding preference of H-NS and Lsr2 for all possible 8-base sequences. Concurrently, we performed a detailed structure-function relationship analysis of their C-terminal DNA binding domains by NMR. Unexpectedly, we found that H-NS and Lsr2 use a common DNA binding mechanism where a short loop containing a "Q/RGR" motif selectively interacts with the DNA minor groove, where the highest affinity is for AT-rich sequences that lack A-tracts. Mutations of the Q/RGR motif abolished DNA binding activity. Netropsin, a DNA minor groove-binding molecule effectively outcompeted H-NS and Lsr2 for binding to AT-rich sequences. These results provide a unified molecular mechanism to explain findings related to xenogeneic silencing proteins, including their lack of apparent sequence specificity but preference for AT-rich sequences. Our findings also suggest that structural information contained within the DNA minor groove is deciphered by xenogeneic silencing proteins to distinguish genetic material that is self from nonself.
- 论文类型：
期刊论文
- 论文编号：
31
- 卷号：
108
- 期号：
26
- 页面范围：
10690-5
- 是否译文：
否
- 发表时间：
2011-06-28
- 收录刊物：
SCI
- 发布期刊链接：
- 第一作者：
Gordon BR
- 通讯作者：
Liu J,Xia B
- 全部作者：
Navarre WW,Hughes TR,Ding P,Weirauch MT,Cote A,Li Y
