BACKGROUND: Eukaryotic DNA replication is initiated from distinct regions on the chromosome. However, the mechanism for recognition of replication origins is not known for most eukaryotes. In fission yeast, replication origins are isolated as autonomously replicating sequences (ARSs). Multiple adenine/thymine clusters are essential for replication, but no short consensus sequences are found. In this paper, we examined the interaction of adenine/thymine clusters with the replication initiation factor ORC. RESULTS: The SpOrc1 or SpOrc2 immunoprecipitates (IPs) containing at least four subunits of SpORC, interacted with the ars2004 fragment, which is derived from a predominant replication origin on the chromosome. SpORC-IPs preferentially interacted with two regions of the ars2004, which consist of consecutive adenines and AAAAT repeats and are essential for ARS activity. The nucleotide sequences required for the interaction with SpORC-IPs correspond closely to those necessary for in vivo ARS activity. CONCLUSION: Our results suggest that the SpORC interacts with adenine/thymine stretches, which have been shown to be the most important component in the fission yeast replication origin. The presence of multiple SpORC-binding sites, with certain sequence variations, is characteristic for the fission yeast replication origins.

This article has been cited by other articles:

				C. R. Houchens, W. Lu, R.-Y. Chuang, M. G. Frattini, A. Fuller, P. Simancek, and T. J. Kelly Multiple Mechanisms Contribute to Schizosaccharomyces pombe Origin Recognition Complex-DNA Interactions J. Biol. Chem., October 31, 2008; 283(44): 30216 - 30224. [Abstract] [Full Text] [PDF]

				S. Stanojcic, J.-M. Lemaitre, K. Brodolin, E. Danis, and M. Mechali In Xenopus Egg Extracts, DNA Replication Initiates Preferentially at or near Asymmetric AT Sequences Mol. Cell. Biol., September 1, 2008; 28(17): 5265 - 5274. [Abstract] [Full Text] [PDF]

				Y. Yamada, T. Nakagawa, and H. Masukata A Novel Intermediate in Initiation Complex Assembly for Fission Yeast DNA Replication Mol. Biol. Cell, August 1, 2004; 15(8): 3740 - 3750. [Abstract] [Full Text] [PDF]

				A. L. Altman and E. Fanning Defined Sequence Modules and an Architectural Element Cooperate To Promote Initiation at an Ectopic Mammalian Chromosomal Replication Origin Mol. Cell. Biol., May 15, 2004; 24(10): 4138 - 4150. [Abstract] [Full Text] [PDF]

				S. Vashee, C. Cvetic, W. Lu, P. Simancek, T. J. Kelly, and J. C. Walter Sequence-independent DNA binding and replication initiation by the human origin recognition complex Genes & Dev., August 1, 2003; 17(15): 1894 - 1908. [Abstract] [Full Text] [PDF]

				W. Feng, L. Rodriguez-Menocal, G. Tolun, and G. D'Urso Schizosacchromyces pombe Dpb2 Binds to Origin DNA Early in S Phase and Is Required for Chromosomal DNA Replication Mol. Biol. Cell, August 1, 2003; 14(8): 3427 - 3436. [Abstract] [Full Text] [PDF]