T. Mizushima et al., EFFECT ON DNA TOPOLOGY BY DNAA PROTEIN, THE INITIATION-FACTOR OF CHROMOSOMAL DNA-REPLICATION IN ESCHERICHIA-COLI, Biochemistry, 35(35), 1996, pp. 11512-11516
We examined effects on supercoiled DNA topology of DnaA protein, the i
nitiator protein of chromosomal DNA replication in Escherichia coli. T
he activity was identified in an analysis of plasmid DNA incubated wit
h 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 topo
logy, binding of the adenine nucleotide may regulate the activity.