PETER BURGERS

..However, Poldelta*-mediated DNA synthesis proceeded inefficiently and was characterized by frequent pause sites. Reconstitution of Poldelta was achieved upon addition of Pol32p to Poldelta*...

..However, Exo5 has the capacity to slide across 5' double-stranded DNA or 5' RNA sequences and resumes cutting two nucleotides downstream of the double-stranded-to-single-stranded junction or RNA-to-DNA junction, respectively...

..In the more common short flap pathway, Pol delta coordinates with the flap endonuclease FEN1 to degrade initiator RNA, whereas in the long flap pathway, RNA removal is initiated by the Dna2 nuclease/helicase...

..When POL31 and POL32 were co-expressed in Escherichia coli, a tetrameric (Pol31p.Pol32p)2 species was detected by gel filtration, indicating that the two subunits form a complex...

..Moreover, a two-hybrid analysis of the Pol32 subunit did not detect a Pol32-Pol32 interaction in vivo. Therefore, we conclude that the assembly structure of Pol delta is that of a monomer...

..The role of DNA polymerase beta in base-excision repair is well established for mammalian systems, but in yeast, DNA polymerase delta appears to fulfill that function...

..These results attest to the structural and functional homology between yeast and mammalian cells for these components of the replication machinery...

..Therefore, DNA repair requires interactions between repair-specific protein(s) and PCNA, which are distinct from those required for DNA replication...

..This interaction is important in the physical orchestration of lagging strand synthesis and may have implications for how PCNA stimulates other members of the FEN-1 nuclease family in a broad range of DNA metabolic transactions...

..An FF-->GA mutation in the PCNA-interaction domain of FEN1 severely decreased both modes of interaction with PCNA and resulted in replication and repair defects in vivo...

..Yeast DNA polymerases I and II and calf thymus DNA polymerase alpha are not stimulated by yPCNA. Treatment of logarithmic-phase cells with hydroxyurea blocks them in the S phase and produces a 4- to 5-fold increase in yPCNA...

..RF-C from the overproduction strain purified by this procedure was essentially homogeneous and had a severalfold higher specific activity than RF-C preparations that had previously been purified through multicolumn procedures...

..coli and purified to homogeneity. Purified Rfc3p has an ATPase activity that is markedly stimulated by single-stranded DNA but not by double-stranded DNA or RNA...

..However, Rfc4p formed a tight complex with the product of the RFC3 gene which encodes the ATPase of RF-C...

..Genetic mapping experiments have localized the UNG1 gene on the left arm of chromosome XIII at 17 cM from the GAL80 locus proximal to the centromer. Deletions of the UNG1 gene are viable...

..These data demonstrate that the ATP binding function of RFC2 is important for both DNA replication and checkpoint function and, for the first time, that RFC4 also plays a role in checkpoint regulation...

..cerevisiae and that the UNG1 gene is not required for strand-specific mismatch repair in S. cerevisiae...

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..Filter binding experiments and analysis of proteins bound to DNA-magnetic beads confirmed the conclusions drawn from the surface plasmon resonance studies...

..RFC.ATP(3); (iv) a conformational change in the latter complex reveals a fourth binding site for ATP; and (v) the DNA.PCNA.RFC.ATP(4) complex is finally competent for completion of PCNA loading and release of RFC upon hydrolysis of ATP...

..We propose that ubiquitination of PCNA increases its functionality as a sliding clamp to promote mutagenic DNA replication...

..Consistent with the hypothesis that DNA polymerase epsilon is the leading-strand enzyme, we observed no idling by this enzyme and no cooperation with FEN1 for creating a ligatable nick...

..We conclude that the three biological functions of the 3'-->5' exonuclease addressed in this study are performed intramolecularly within the replicating holoenzyme...

..We conclude that Pol epsilon and Pol delta exhibit comparable processivity, but are loaded on the primer-end via different mechanisms...

..By contrast, RFC and PCNA have only a limited effect on 5' to 3' excision directed by a 5' strand break...

..In agreement, overexpression of DDC1 or RAD17 in a MEC3Delta strain, or of MEC3 or RAD17 in a DDC1Delta strain shows no rescue of damage sensitivity...

..We conclude that histone chaperone protein Asf1 maintains a subset of replication elongation factors at stalled replication forks and directly interacts with the replication machinery...

..Improper regulation of these processes in humans may lead to cancer. ..

..Improper function and regulation of these processes in humans may lead to the accumulation of mutations and cancer. ..

..Improper function and regulation of these processes in humans may lead to the accumulation of mutations and chromosome abnormalities, and in cancer. ..

..Checkpoint pathways are conserved from human to yeast, and we are proposing to study these pathways in yeast, because as a model organism it is more approachable to genetic and biochemical analysis. ..

..These pathways are conserved from human to yeast, and we are proposing to study these pathways in yeast, because this model organism is more approachable to genetic and biochemical analysis. ..

..Checkpoint pathways are conserved from human to yeast, and we are proposing to study these pathways in yeast, because as a model organism it is more approachable to genetic and biochemical analysis. ..

..Improper regulation of these processes in humans may lead to cancer. ..

..Thus, an intensive study of the mechanism of DNA replication and its regulation in yeast will aid in understanding the mechanisms that induce or prevent mutations as well as those that control cell division in human cells...

..In addition, a better understanding of the mechanisms that induce or prevent mutations in yeast may lead to a better understanding of similar mechanisms in humans...

..These pathways are conserved from human to yeast, and we are proposing to study these pathways in yeast, because this model organism is more approachable to genetic and biochemical analysis. ..