The S. cerevisiae Rrm3p DNA helicase moves with the replication fork and affects replication of all yeast chromosomes.
The Saccharomyces cerevisiae DNA helicase Rrm3p is needed for normal fork progression through >1000 discrete sites scattered throughout the genome. Here we show that replication of all yeast chromosomes was markedly delayed in rrm3 cells. Delayed replication was seen even in a region that lacks any predicted Rrm3p-dependent sites. Based on the pattern of replication intermediates in two-dimensional gels, the rate of fork movement in rrm3 cells appeared similar to wild-type except at known Rrm3p-dependent sites. These data suggest that although Rrm3p has a global role in DNA replication, its activity is needed only or primarily at specific, difficult-to-replicate sites. By the criterion of chromatin immunoprecipitation, Rrm3p was associated with both Rrm3p-dependent and -independent sites, and moved with the replication fork through both. In addition, Rrm3p interacted with Pol2p, the catalytic subunit of DNA polymerase epsilon, in vivo. Thus, rather than being recruited to its sites of action when replication forks stall at these sites, Rrm3p is likely a component of the replication fork apparatus.
Azvolinsky
Anna
A
Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA.
Dunaway
Stephen
S
Torres
Jorge Z
JZ
Bessler
Jessica B
JB
Zakian
Virginia A
VA
D018797:Cell Cycle Proteins / Q000378:metabolism; D015825:Chromosomes, Fungal / Q000378:metabolism*; D004265:DNA Helicases / Q000378:metabolism*; D004261:DNA Replication; D004271:DNA, Fungal / Q000096:biosynthesis; D004275:DNA, Ribosomal / Q000096:biosynthesis / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D064148:Minichromosome Maintenance Complex Component 4; D011485:Protein Binding; D021381:Protein Transport; D016196:S Phase; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
D018797:Cell Cycle Proteins; D004271:DNA, Fungal; D004275:DNA, Ribosomal; D004268:DNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; C459081:Rrm3 protein, S cerevisiae; D004265:DNA Helicases; C092802:MCM4 protein, S cerevisiae; D064148:Minichromosome Maintenance Complex Component 4