Szalewska-Palasz A, Weigel C, Speck C, Srutkowska S, Konopa G, Lurz R, Marszalek J, Taylor K, Messer W, Wegrzyn G
Department of Molecular Biology, University of Gdañsk, Poland.
Mol Gen Genet. 1998 Oct;259(6):679-88. doi: 10.1007/s004380050863.
Interaction of the Escherichia coli DnaA (replication initiator) protein with restriction fragments of phage lambda DNA demonstrated differential binding of DnaA along the whole lambda DNA. Interaction of DnaA with the lambda replication region (from the promoter pR to the origin of replication, orilambda) demonstrated a strong binding of DnaA to the region around the p(o) promoter where synthesis of a short antisense oop RNA is initiated. The four sequences protected by DnaA (two 9mers and two 5mers) are not related even to a relaxed DnaA box. The pattern of protection of these four sequences and the location of three DNase I hypersensitive sites in the lambda DNA r strand, together with results of mobility shift assays and electron microscopy studies, may indicate an interaction involving DnaA monomers bound to different DNA positions on one side of the helix and the formation of higher-order nucleoprotein structures. Therefore, it is tempting to suggest that DnaA, in addition to its activity in regulation of replication and transcription, could be considered as a factor which structures certain chromosomal regions.
大肠杆菌DnaA（复制起始蛋白）与噬菌体λ DNA的限制性片段的相互作用表明，DnaA沿着整个λ DNA存在差异结合。DnaA与λ复制区域（从启动子pR到复制起点orilambda）的相互作用表明，DnaA与p(o)启动子周围区域有强烈结合，在该区域开始合成短的反义oop RNA。受DnaA保护的四个序列（两个9聚体和两个5聚体）甚至与宽松的DnaA框都不相关。这四个序列的保护模式以及λ DNA r链中三个DNase I超敏位点的位置，连同迁移率变动分析和电子显微镜研究的结果，可能表明存在一种相互作用，涉及结合在螺旋一侧不同DNA位置的DnaA单体以及高阶核蛋白结构的形成。因此，很诱人地提出，除了其在复制和转录调控中的活性外，DnaA还可被视为一种构建某些染色体区域的因子。
