Biomaterial Database

DNA binding, annealing, and strand exchange activities of Brh2 protein from Ustilago maydis. 2007

Nayef Mazloum, and Qingwen Zhou, and William K Holloman

Department of Microbiology and Immunology, Cornell University Weill Medical College, New York, New York 10021, USA.

Brh2 is the Ustilago maydis ortholog of the BRCA2 tumor suppressor. It functions in repair of DNA by homologous recombination by controlling the action of Rad51. A critical aspect in the control appears to be the recruitment of Rad51 to single-stranded DNA regions exposed as lesions after damage or following a disturbance in DNA synthesis. In previous experimentation, Brh2 was shown to nucleate formation of the Rad51 nucleoprotein filament that becomes the active element in promoting homologous pairing and DNA strand exchange. Nucleation was found to be initiated at junctions of double-stranded and single-stranded DNA. Here we investigated the DNA binding specificity of Brh2 in more detail using oligonucleotide substrates. We observed that Brh2 prefers partially duplex structures with single-stranded branches, flaps, or D-loops. We found also that Brh2 has an inherent ability to promote DNA annealing and strand exchange reactions on free as well as RPA-coated substrates. Unlike Rad51, Brh2 was able to promote DNA strand exchange when preincubated with double-stranded DNA. These findings raise the notion that Brh2 may have roles in homologous recombination beyond the previously established Rad51 mediator activity.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D011994	Recombinant Proteins	Proteins prepared by recombinant DNA technology.	Biosynthetic Protein,Biosynthetic Proteins,DNA Recombinant Proteins,Recombinant Protein,Proteins, Biosynthetic,Proteins, Recombinant DNA,DNA Proteins, Recombinant,Protein, Biosynthetic,Protein, Recombinant,Proteins, DNA Recombinant,Proteins, Recombinant,Recombinant DNA Proteins,Recombinant Proteins, DNA
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D004260	DNA Repair	The removal of DNA LESIONS and/or restoration of intact DNA strands without BASE PAIR MISMATCHES, intrastrand or interstrand crosslinks, or discontinuities in the DNA sugar-phosphate backbones.	DNA Damage Response
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
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
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
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
D014588	Ustilago	A genus of basidiomycetous smut fungi comprising the loose smuts.	Ustilagos
D051017	Apoptosis Regulatory Proteins	A large group of proteins that control APOPTOSIS. This family of proteins includes many ONCOGENE PROTEINS as well as a wide variety of classes of INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS such as CASPASES.	Anti-Apoptotic Protein,Anti-Apoptotic Proteins,Apoptosis Inducing Protein,Apoptosis Inhibiting Protein,Apoptosis Regulatory Protein,Pro-Apoptotic Protein,Pro-Apoptotic Proteins,Programmed Cell Death Protein,Apoptosis Inducing Proteins,Apoptosis Inhibiting Proteins,Death Factors (Apoptosis),Programmed Cell Death Proteins,Survival Factors (Apoptosis),Anti Apoptotic Protein,Anti Apoptotic Proteins,Inducing Protein, Apoptosis,Inducing Proteins, Apoptosis,Inhibiting Protein, Apoptosis,Inhibiting Proteins, Apoptosis,Pro Apoptotic Protein,Pro Apoptotic Proteins,Protein, Anti-Apoptotic,Protein, Apoptosis Inducing,Protein, Apoptosis Inhibiting,Protein, Apoptosis Regulatory,Protein, Pro-Apoptotic,Proteins, Anti-Apoptotic,Proteins, Apoptosis Inducing,Proteins, Apoptosis Inhibiting,Proteins, Pro-Apoptotic,Regulatory Protein, Apoptosis,Regulatory Proteins, Apoptosis