Mizushima T, Katayama T, Sekimizu K
Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
Biochemistry. 1996 Sep 3;35(35):11512-6. doi: 10.1021/bi953088f.
We examined effects on supercoiled DNA topology of DnaA protein, the initiator protein of chromosomal DNA replication in Escherichia coli. The activity was identified in an analysis of plasmid DNA incubated with DnaA protein and DNA topoisomerase I. In Superose 12 gel filtration chromatography, the activity coeluted with DnaA protein. Incubation of DnaA protein with DNA at temperatures over 24 degrees C was required for this activity, which was observed with either oriC plasmid or the replicative form I of phi X174 with no DnaA box. As binding of ATP or ADP to DnaA protein prevented the activity of DnaA protein on DNA topology, binding of the adenine nucleotide may regulate the activity.
我们研究了大肠杆菌染色体DNA复制起始蛋白DnaA对超螺旋DNA拓扑结构的影响。该活性是在对与DnaA蛋白和DNA拓扑异构酶I一起孵育的质粒DNA进行分析时确定的。在Superose 12凝胶过滤色谱中，该活性与DnaA蛋白共洗脱。此活性需要DnaA蛋白与DNA在24摄氏度以上的温度下孵育，在oriC质粒或没有DnaA框的phi X174复制形式I中均能观察到该活性。由于ATP或ADP与DnaA蛋白的结合会阻止DnaA蛋白对DNA拓扑结构的活性，腺嘌呤核苷酸的结合可能会调节该活性。
