| Project/Area Number |
21770187
|
|---|
| Research Category |
Grant-in-Aid for Young Scientists (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Molecular biology
|
|---|
| Research Institution | Kyushu University |
|---|
Principal Investigator |
OZAKI Shogo Kyushu University, 薬学研究院, 助教 (70510147)
|
|---|
| Project Period (FY) |
2009 – 2010
|
| Project Status |
Completed (Fiscal Year 2010)
|
| Budget Amount *help |
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2010: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2009: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
|
|---|
| Keywords | DnaA / 複製開始 / 高次複合体 / AAA+ / 2重鎖DNA弛緩 / DNA複製開始 / 構造変化 / 構造・活性相関 |
|---|
| 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.
|
