HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE ADVANCED SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ozaki, S. Articles by Katayama, T. Search for Related Content PubMed PubMed Citation Articles by Ozaki, S. Articles by Katayama, T.

¹ Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
² Graduate School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan

In Escherichia coli, ATP-DnaA, but not ADP-DnaA, forms an initiation complex that undergoes site-specific duplex DNA unwinding, open complex formation. However, it remains unclear how highly the ATP-dependent activation of the initiation factor is conserved in evolution. The hyperthermophile Thermotoga maritima is one of the most ancient eubacteria in evolution. Here, we show that the DnaA homolog (tmaDnaA) of this bacterium forms open complexes with the predicted origin region (tma-oriC) in vitro. TmaDnaA has a strong and specific affinity for ATP/ADP as well as for 12-mer repeating sequences within the tma-oriC. Unlike ADP-tmaDnaA, ATP-tmaDnaA is highly cooperative in DNA binding and forms open complexes in a manner that depends on temperature and the superhelical tension of the tma-oriC-bearing plasmid. The minimal tma-oriC required for unwinding is a 149-bp region containing five repeats of the 12-mer sequence and two AT-rich 9-mer repeats. TmaDnaA-binding to the 12-mer motif provokes DNA bending. The 9-mer region is the duplex-unwinding site. The tmaDnaA-binding and unwinding motifs of tma-oriC share sequence homology with corresponding archaeal and eukaryotic sequences. These findings suggest that the ATP-dependent molecular switch of the initiator and the mechanisms in the replication initiation complex are highly conserved in eubacterial evolution.

^* Correspondence: E-mail: katayama{at}phar.kyushu-u.ac.jp

This article has been cited by other articles:

				S. Ozaki, H. Kawakami, K. Nakamura, N. Fujikawa, W. Kagawa, S.-Y. Park, S. Yokoyama, H. Kurumizaka, and T. Katayama A Common Mechanism for the ATP-DnaA-dependent Formation of Open Complexes at the Replication Origin J. Biol. Chem., March 28, 2008; 283(13): 8351 - 8362. [Abstract] [Full Text] [PDF]

				K. Keyamura, N. Fujikawa, T. Ishida, S. Ozaki, M. Su'etsugu, K. Fujimitsu, W. Kagawa, S. Yokoyama, H. Kurumizaka, and T. Katayama The interaction of DiaA and DnaA regulates the replication cycle in E. coli by directly promoting ATP DnaA-specific initiation complexes Genes & Dev., August 15, 2007; 21(16): 2083 - 2099. [Abstract] [Full Text] [PDF]

				H. Pei, J. Liu, J. Li, A. Guo, J. Zhou, and H. Xiang Mechanism for the TtDnaA-Tt-oriC cooperative interaction at high temperature and duplex opening at an unusual AT-rich region in Thermoanaerobacter tengcongensis Nucleic Acids Res., May 14, 2007; 35(9): 3087 - 3099. [Abstract] [Full Text] [PDF]