Rapid turnover of DnaA at replication origin regions contributes to initiation control of DNA replication.
DnaA is a conserved key regulator of replication initiation in bacteria, and is homologous to ORC proteins in archaea and in eukaryotic cells. The ATPase binds to several high affinity binding sites at the origin region and upon an unknown molecular trigger, spreads to several adjacent sites, inducing the formation of a helical super structure leading to initiation of replication. Using FRAP analysis of a functional YFP-DnaA allele in Bacillus subtilis, we show that DnaA is bound to oriC with a half-time of 2.5 seconds. DnaA shows similarly high turnover at the replication machinery, where DnaA is bound to DNA polymerase via YabA. The absence of YabA increases the half time binding of DnaA at oriC, showing that YabA plays a dual role in the regulation of DnaA, as a tether at the replication forks, and as a chaser at origin regions. Likewise, a deletion of soj (encoding a ParA protein) leads to an increase in residence time and to overinitiation, while a mutation in DnaA that leads to lowered initiation frequency, due to a reduced ATPase activity, shows a decreased residence time on binding sites. Finally, our single molecule tracking experiments show that DnaA rapidly moves between chromosomal binding sites, and does not arrest for more than few hundreds of milliseconds. In Escherichia coli, DnaA also shows low residence times in the range of 200 ms and oscillates between spatially opposite chromosome regions in a time frame of one to two seconds, independently of ongoing transcription. Thus, DnaA shows extremely rapid binding turnover on the chromosome including oriC regions in two bacterial species, which is influenced by Soj and YabA proteins in B. subtilis, and is crucial for balanced initiation control, likely preventing fatal premature multimerization and strand opening of DnaA at oriC.
SYNMIKRO, LOEWE Center for Synthetic Microbiology, Marburg, Germany.|Department of Chemistry, Philipps Universität Marburg, Marburg, Germany.
Katrin
K
Schenk
SYNMIKRO, LOEWE Center for Synthetic Microbiology, Marburg, Germany.|Department of Chemistry, Philipps Universität Marburg, Marburg, Germany.
Ana B
AB
Hervás
SYNMIKRO, LOEWE Center for Synthetic Microbiology, Marburg, Germany.|Department of Chemistry, Philipps Universität Marburg, Marburg, Germany.
Thomas C
TC
Rösch
SYNMIKRO, LOEWE Center for Synthetic Microbiology, Marburg, Germany.|Department of Chemistry, Philipps Universität Marburg, Marburg, Germany.
Marc
M
Eisemann
SYNMIKRO, LOEWE Center for Synthetic Microbiology, Marburg, Germany.|Department of Mathematics, Philipps Universität Marburg, Marburg, Germany.
Bernhard A
0000-0001-5797-8024
BA
Schmitt
SYNMIKRO, LOEWE Center for Synthetic Microbiology, Marburg, Germany.|Department of Mathematics, Philipps Universität Marburg, Marburg, Germany.
Stephan
S
Dahlke
SYNMIKRO, LOEWE Center for Synthetic Microbiology, Marburg, Germany.|Department of Chemistry, Philipps Universität Marburg, Marburg, Germany.
Luise
L
Kleine-Borgmann
SYNMIKRO, LOEWE Center for Synthetic Microbiology, Marburg, Germany.|Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
Seán M
SM
Murray
SYNMIKRO, LOEWE Center for Synthetic Microbiology, Marburg, Germany.|Department of Chemistry, Philipps Universität Marburg, Marburg, Germany.
Peter L
PL
Graumann
D000251:Adenosine Triphosphatases / Q000235:genetics; D001412:Bacillus subtilis / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics*; D004261:DNA Replication / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D009154:Mutation; D051738:Origin Recognition Complex / Q000235:genetics*; D018741:Replication Origin / Q000235:genetics
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C066312:DnaA protein, Bacteria; C114650:OriC chromosomal replication origin; D051738:Origin Recognition Complex; D000251:Adenosine Triphosphatases