抄録
Escherichia coli DnaA binds to 9 bp sequences (DnaA boxes) in the replication origin, oriC, to form a complex initiating chromosomal DNA replication. In the present study, we determined the crystal structure of its DNA-binding domain (domain IV) complexed with a DnaA box at 2.1 Å resolution. DnaA domain IV contains a helix-turn-helix motif for DNA binding. One helix and a loop of the helix-turn-helix motif are inserted into the major groove and 5 bp (3′ two-thirds of the DnaA box sequence) are recognized through base-specific hydrogen bonds and van der Waals contacts with the C5-methyl groups of thymines. In the minor groove, Arg399, located in the loop adjacent to the motif, recognizes three more base pairs (5′ one-third of the DnaA box sequence) by base-specific hydrogen bonds. DNA bending by ∼28° was also observed in the complex. These base-specific interactions explain how DnaA exhibits higher affinity for the strong DnaA boxes (R1, R2 and R4) than the weak DnaA boxes (R3 and M) in the replication origin.
本文言語 | English |
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ページ(範囲) | 2077-2086 |
ページ数 | 10 |
ジャーナル | Nucleic Acids Research |
巻 | 31 |
号 | 8 |
DOI | |
出版ステータス | Published - 2003 4月 15 |
外部発表 | はい |
ASJC Scopus subject areas
- 遺伝学