Biomaterial Database

Subunit interactions within the Saccharomyces cerevisiae DNA polymerase epsilon (pol epsilon ) complex. Demonstration of a dimeric pol epsilon. 2000

R Dua, and S Edwards, and D L Levy, and J L Campbell

Braun Laboratories, California Institute of Technology, Pasadena, California 91125, USA.

Saccharomyces cerevisiae DNA polymerase epsilon (pol epsilon) is essential for chromosomal replication. A major form of pol epsilon purified from yeast consists of at least four subunits: Pol2p, Dpb2p, Dpb3p, and Dpb4p. We have investigated the protein/protein interactions between these polypeptides by using expression of individual subunits in baculovirus-infected Sf9 insect cells and by using the yeast two-hybrid assay. The essential subunits, Pol2p and Dpb2p, interact directly in the absence of the other two subunits, and the C-terminal half of POL2, the only essential portion of Pol2p, is sufficient for interaction with Dpb2p. Dpb3p and Dpb4p, non-essential subunits, also interact directly with each other in the absence of the other two subunits. We propose that Pol2p.Dpb2p and Dpb3p.Dpb4p complexes interact with each other and document several interactions between individual members of the two respective complexes. We present biochemical evidence to support the proposal that pol epsilon may be dimeric in vivo. Gel filtration of the Pol2p.Dpb2p complexes reveals a novel heterotetrameric form, consisting of two heterodimers of Pol2p.Dpb2p. Dpb2p, but not Pol2p, exists as a homodimer, and thus the Pol2p dimerization may be mediated by Dpb2p. The pol2-E and pol2-F mutations that cause replication defects in vivo weaken the interaction between Pol2p and Dpb2p and also reduce dimerization of Pol2p. This suggests, but does not prove, that dimerization may also occur in vivo and be essential for DNA replication.

UI	MeSH Term	Description	Entries
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D002850	Chromatography, Gel	Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.	Chromatography, Exclusion,Chromatography, Gel Permeation,Chromatography, Molecular Sieve,Gel Filtration,Gel Filtration Chromatography,Chromatography, Size Exclusion,Exclusion Chromatography,Gel Chromatography,Gel Permeation Chromatography,Molecular Sieve Chromatography,Chromatography, Gel Filtration,Exclusion Chromatography, Size,Filtration Chromatography, Gel,Filtration, Gel,Sieve Chromatography, Molecular,Size Exclusion Chromatography
D004257	DNA Polymerase II	A DNA-dependent DNA polymerase characterized in E. coli and other lower organisms. It may be present in higher organisms and has an intrinsic molecular activity only 5% of that of DNA Polymerase I. This polymerase has 3'-5' exonuclease activity, is effective only on duplex DNA with gaps or single-strand ends of less than 100 nucleotides as template, and is inhibited by sulfhydryl reagents.	DNA Polymerase epsilon,DNA-Dependent DNA Polymerase II,DNA Pol II,DNA Dependent DNA Polymerase II
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012441	Saccharomyces cerevisiae	A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.	Baker's Yeast,Brewer's Yeast,Candida robusta,S. cerevisiae,Saccharomyces capensis,Saccharomyces italicus,Saccharomyces oviformis,Saccharomyces uvarum var. melibiosus,Yeast, Baker's,Yeast, Brewer's,Baker Yeast,S cerevisiae,Baker's Yeasts,Yeast, Baker
D013329	Structure-Activity Relationship	The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.	Relationship, Structure-Activity,Relationships, Structure-Activity,Structure Activity Relationship,Structure-Activity Relationships
D016335	Zinc Fingers	Motifs in DNA- and RNA-binding proteins whose amino acids are folded into a single structural unit around a zinc atom. In the classic zinc finger, one zinc atom is bound to two cysteines and two histidines. In between the cysteines and histidines are 12 residues which form a DNA binding fingertip. By variations in the composition of the sequences in the fingertip and the number and spacing of tandem repeats of the motif, zinc fingers can form a large number of different sequence specific binding sites.	Zinc Finger DNA-Binding Domains,Zinc Finger Motifs,Finger, Zinc,Fingers, Zinc,Motif, Zinc Finger,Motifs, Zinc Finger,Zinc Finger,Zinc Finger DNA Binding Domains,Zinc Finger Motif
D017354	Point Mutation	A mutation caused by the substitution of one nucleotide for another. This results in the DNA molecule having a change in a single base pair.	Mutation, Point,Mutations, Point,Point Mutations
D018411	Spodoptera	A genus of owlet moths of the family Noctuidae. These insects are used in molecular biology studies during all stages of their life cycle.	Spodoptera frugiperda,Spodoptera frugiperdas,Spodopteras,frugiperdas, Spodoptera
D019281	Dimerization	The process by which two molecules of the same chemical composition form a condensation product or polymer.	Dimerizations