Biomaterial Database

The Saccharomyces Pif1p DNA helicase and the highly related Rrm3p have opposite effects on replication fork progression in ribosomal DNA. 2000

A S Ivessa, and J Q Zhou, and V A Zakian

Department of Molecular Biology, Princeton University, New Jersey 08544-1014, USA.

Replication of Saccharomyces ribosomal DNA (rDNA) proceeds bidirectionally from origins in a subset of the approximately 150 tandem repeats, but the leftward-moving fork stops when it encounters the replication fork barrier (RFB). The Pif1p helicase and the highly related Rrm3p were rDNA associated in vivo. Both proteins affected rDNA replication but had opposing effects on fork progression. Pif1p helped maintain the RFB. Rrm3p appears to be the replicative helicase for rDNA as it acted catalytically to promote fork progression throughout the rDNA. Loss of Rrm3p increased rDNA breakage and accumulation of rDNA circles, whereas breakage and circles were less common in pif1 cells. These data support a model in which replication fork pausing causes breakage and recombination in the rDNA.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D002384	Catalysis	The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.	Catalyses
D004261	DNA Replication	The process by which a DNA molecule is duplicated.	Autonomous Replication,Replication, Autonomous,Autonomous Replications,DNA Replications,Replication, DNA,Replications, Autonomous,Replications, DNA
D004265	DNA Helicases	Proteins that catalyze the unwinding of duplex DNA during replication by binding cooperatively to single-stranded regions of DNA or to short regions of duplex DNA that are undergoing transient opening. In addition, DNA helicases are DNA-dependent ATPases that harness the free energy of ATP hydrolysis to translocate DNA strands.	ATP-Dependent DNA Helicase,DNA Helicase,DNA Unwinding Protein,DNA Unwinding Proteins,ATP-Dependent DNA Helicases,DNA Helicase A,DNA Helicase E,DNA Helicase II,DNA Helicase III,ATP Dependent DNA Helicase,ATP Dependent DNA Helicases,DNA Helicase, ATP-Dependent,DNA Helicases, ATP-Dependent,Helicase, ATP-Dependent DNA,Helicase, DNA,Helicases, ATP-Dependent DNA,Helicases, DNA,Protein, DNA Unwinding,Unwinding Protein, DNA,Unwinding Proteins, DNA
D004268	DNA-Binding Proteins	Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.	DNA Helix Destabilizing Proteins,DNA-Binding Protein,Single-Stranded DNA Binding Proteins,DNA Binding Protein,DNA Single-Stranded Binding Protein,SS DNA BP,Single-Stranded DNA-Binding Protein,Binding Protein, DNA,DNA Binding Proteins,DNA Single Stranded Binding Protein,DNA-Binding Protein, Single-Stranded,Protein, DNA-Binding,Single Stranded DNA Binding Protein,Single Stranded DNA Binding Proteins
D004271	DNA, Fungal	Deoxyribonucleic acid that makes up the genetic material of fungi.	Fungal DNA
D004275	DNA, Ribosomal	DNA sequences encoding RIBOSOMAL RNA and the segments of DNA separating the individual ribosomal RNA genes, referred to as RIBOSOMAL SPACER DNA.	Ribosomal DNA,rDNA
D005656	Fungal Proteins	Proteins found in any species of fungus.	Fungal Gene Products,Fungal Gene Proteins,Fungal Peptides,Gene Products, Fungal,Yeast Proteins,Gene Proteins, Fungal,Peptides, Fungal,Proteins, Fungal
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA