Complex mechanism of site-specific DNA replication termination in fission yeast.
A site-specific replication terminator, RTS1, is present at the Schizosaccharomyces pombe mating-type locus mat1. RTS1 regulates the direction of replication at mat1, optimizing mating-type switching that occurs as a replication-coupled recombination event. Here we show that RTS1 contains two cis-acting sequences that cooperate for efficient replication termination. First, a sequence of approximately 450 bp containing four repeated 55 bp motifs is essential for function. Secondly, a purine-rich sequence of approximately 60 bp without intrinsic activity, located proximal to the repeats, acts cooperatively to increase barrier activity 4-fold. Our data suggest that the trans-acting factors rtf1p and rtf2p act through the repeated motifs and the purine-rich element, respectively. Thus, efficient site-specific replication termination at RTS1 occurs by a complex mechanism involving several cis-acting sequences and trans-acting factors. Interestingly, RTS1 displays similarities to mammalian rDNA replication barriers.
Codlin
Sandra
S
Marie Curie Research Institute, The Chart, Oxted, Surrey RH8 0TL, UK.
Dalgaard
Jacob Z
JZ
D001483:Base Sequence; D004261:DNA Replication; D004271:DNA, Fungal / Q000096:biosynthesis*; D005816:Genetic Complementation Test; D009154:Mutation; D011995:Recombination, Genetic; D012568:Schizosaccharomyces / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D013728:Terminator Regions, Genetic; D014158:Transcription, Genetic
D004271:DNA, Fungal