2010 Fiscal Year Final Research Report
Mechanisms for ATP-dependent activation of highly-ordered complex formed by the initiator protein DnaA.
| Project/Area Number |
21770187
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Molecular biology
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| Research Institution | Kyushu University |
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Principal Investigator |
OZAKI Shogo Kyushu University, 薬学研究院, 助教 (70510147)
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| Project Period (FY) |
2009 – 2010
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| Keywords | DnaA / 複製開始 / 高次複合体 / AAA+ / 2重鎖DNA弛緩 |
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| Research Abstract |
ATP-DnaA multimerize on the DnaA-assembly region (DAR) of the replication origin oriC, unwinding the duplex unwinding element (DUE) flanking DAR. The ATP-DnaA-oriC complex binds the resultant single-stranded (ss)DUE, promoting DnaB helicase loading. However, mechanisms in DUE unwinding remain unclear. Here, using various in vitro reconstituted systems, we identify functionally distinct DnaA sub-complexes formed on DAR and reveal their specific roles and novel mechanisms in DUE unwinding. The DUE-flanking left-half DAR carrying high-affinity DnaA box R1 and several ATP-DnaA-preferential sites formed a DnaA sub-complex competent to DUE unwinding and ssDUE binding, thereby supporting basal DnaB loading activity. This sub-complex is further subdivided to two ; The DUE-distal DnaA sub-complex formed on the ATP-DnaA-preferential sites binds ssDUE. The DUE-flanking DnaA sub-complex formed on DnaA box R1 recruits DUE to the DUE-distal DnaA sub-complex cooperatively with a DNA-bending protein IHF, promoting initiation. These dynamics in the initial complexes are likely conserved in eubacterial evolution.
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[Presentation] DnaA, the replication initiator, is activated for the timely initiation of the chromosomal replication by a specific DNA element, DARS.2011
Author(s)
Fujimitsu, K., Kasho, K., Ozaki, S., Keyamura, K., Katayama, T.
Organizer
International Symposium on the Physicochemical Field for Genetic Activities, Session 5
Place of Presentation
Hyogo, Japan
Year and Date
20110000
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[Presentation] DARS, DnaA-reactivating sequence promotes exchange of DnaA-bound ADP to ATP.2010
Author(s)
Fujimitsu, K., Kasho, K., Ozaki, S., Senriuchi, T., Katayama, T.
Organizer
EMBO Workshop on Replication/Repair & Segregation of Chromosomes
Place of Presentation
Freiburg, Germany
Year and Date
20100000
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