期刊
NUCLEIC ACIDS RESEARCH
卷 43, 期 2, 页码 719-731出版社
OXFORD UNIV PRESS
DOI: 10.1093/nar/gku1295
关键词
-
资金
- European Research Council [206117]
- Spanish Ministry of Economy and Competitiveness [FIS2011-24638]
- Wellcome Trust [077368, 100401]
- Research Foundation Flanders
- European Research Council (ERC) [206117] Funding Source: European Research Council (ERC)
The segregation of many bacterial chromosomes is dependent on the interactions of ParB proteins with centromere-like DNA sequences called parS that are located close to the origin of replication. In this work, we have investigated the binding of Bacillus subtilis ParB to DNA in vitro using a variety of biochemical and biophysical techniques. We observe tight and specific binding of a ParB homodimer to the parS sequence. Binding of ParB to non-specific DNA is more complex and displays apparent positive cooperativity that is associated with the formation of larger, poorly defined, nucleoprotein complexes. Experiments with magnetic tweezers demonstrate that non-specific binding leads to DNA condensation that is reversible by protein unbinding or force. The condensed DNA structure is not well ordered and we infer that it is formed by many looping interactions between neighbouring DNA segments. Consistent with this view, ParB is also able to stabilize writhe in single supercoiled DNA molecules and to bridge segments from two different DNA molecules in trans. The experiments provide no evidence for the promotion of nonspecific DNA binding and/or condensation events by the presence of parS sequences. The implications of these observations for chromosome segregation are discussed.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据