Open AccessThe fission yeast homologue of Orc4p binds to replication origin DNA via multiple AT-hooks
Author(s) -
Ronald Y. Chuang,
Thomas J. Kelly
Publication year - 1999
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.96.6.2656
Subject(s) - schizosaccharomyces pombe , origin recognition complex , biology , control of chromosome duplication , dna replication , schizosaccharomyces , origin of replication , eukaryotic dna replication , saccharomyces cerevisiae , pre replication complex , replication factor c , hmg box , dna , genetics , dna binding domain , microbiology and biotechnology , yeast , dna binding protein , gene , transcription factor
The origin recognition complex (ORC) was originally identified in the yeastSaccharomyces cerevisiae as a protein that specifically binds to origins of DNA replication. Although ORC appears to play an essential role in the initiation of DNA replication in the cells of all eukaryotes, its interactions with DNA have not been defined in species other than budding yeast. We have characterized aSchizosaccharomyces pombe homologue of the ORC subunit, Orc4p. The homologue (Orp4p) consists of two distinct functional domains. The C-terminal domain shows strong sequence similarity to human, frog, and yeast Orc4 proteins, including conserved ATP-binding motifs. The N-terminal domain contains nine copies of the AT-hook motif found in a number of DNA-binding proteins, including the members of the HMG-I(Y) family of chromatin proteins. AT-hook motifs are known from biochemical and structural studies to mediate binding to the minor groove of AT-tracts in DNA. Orp4p is essential for viability ofSc. pombe and is expressed throughout the cell cycle. The Orp4 protein (and its isolated N-terminal domain) binds to theSc. pombe replication origin,ars1 . The DNA binding properties of Orp4p provide a plausible explanation for the characteristic features ofSc. pombe origins of replication, which differ significantly from those ofSa. cerevisiae .