AFM studies on the role of the protein RdgC in bacterial DNA recombination.
AFM studies on the role of the protein RdgC in bacterial DNA recombination.
复制标题
DOI：
10.1016/j.jmb.2005.04.043
复制
发表时间：
2005-07
影响因子：
5.6
通讯作者：
I. Tessmer;T. Moore;R. Lloyd;A. Wilson;D. Erie;S. Allen;S. Tendler
中科院分区：
文献类型：
--
作者：
I. Tessmer;T. Moore;R. Lloyd;A. Wilson;D. Erie;S. Allen;S. Tendler
RdgC在不同细菌系统中的遗传学研究表明，它可能在复制和重组中发挥作用。然而，相应的蛋白质RdgC的确切功能尚不清楚。在这项研究中，我们用原子力显微镜对RdgC与线形和超螺旋环状DNA的复合物进行了成像。我们证实，RdgC并不像生化数据所表明的那样，针对双链DNA中的任何特定序列。然而，我们检测到蛋白质与DNA末端的亲和力增加，并有能力促进DNA的弯曲。据报道，参与重组的酶具有类似的结合偏好。RdgC与超螺旋DNA的蛋白质络合物使我们能够进一步研究RdgC对DNA超结构的影响。在高浓度的蛋白质中，我们观察到DNA缩合的促进作用。重组在很大程度上是通过沿DNA链的远处区域的紧密接触来增强的，例如，通过缩合。因此，我们的数据支持RdgC作为重组的助产士的可能功能。
Genetic studies of rdgC in different bacterial systems suggest that it may play a role in replication and recombination. However, the exact function of the corresponding protein, RdgC, is unknown. In this study, we have imaged complexes of RdgC with both linear and supercoiled circular plasmid DNA using atomic force microscopy. We confirm that RdgC does not target any specific sequences in double-stranded DNA, as has been suggested from biochemical data. However, we detect an increased affinity of the protein to DNA ends, and an ability to promote bending of DNA. Similar binding preferences have been reported for enzymes involved in recombination. Protein complexes with supercoiled plasmid DNA further enabled us to study the effect of RdgC on DNA superstructure. At high concentrations of protein we observed promotion of DNA condensation. Recombination is largely enhanced by close contacts of distant regions along the DNA strands, as can occur, for instance, through condensation. Our data thus support a possible function of RdgC as a midwife of recombination.