Creating Directed Double-strand Breaks with the Ref Protein

Creating directed double-strand breaks with the Ref protein: a novel RecA-dependent nuclease from bacteriophage P1.

The bacteriophage P1-encoded Ref protein enhances RecA-dependent recombination in vivo by an unknown mechanism. We demonstrate that Ref is a new type of enzyme; that is, a RecA-dependent nuclease. Ref binds to ss- and dsDNA but does not cleave any DNA substrate until RecA protein and ATP are added to form RecA nucleoprotein filaments. Ref cleaves only where RecA protein is bound. RecA functions...

Creating Localized DNA Double-Strand Breaks Using Micro-Irradiation

DNA Double-Strand Breaks

The activation-induced cytidine deaminase (AID) is required for somatic hypermutation (SHM) and class-switch recombination (CSR) of immunoglobulin (Ig) genes, both of which are associated with DNA double-strand breaks (DSBs). As AID is capable of deaminating deoxy-cytidine (dC) to deoxy-uracil (dU), it might induce nicks (single strand DNA breaks) and also DNA DSBs via a U-DNA glycosylase-media...

Coping with DNA double strand breaks.

The repair of DNA double strand breaks (dsb) is important for maintaining the physical and genetic integrity of the genome. Moreover, in humans it is associated with the prevention of diseases such as immune deficiencies and cancer. This review briefly explores the fundamental strategies for repairing dsb, examines how cells maximize the fidelity of dsb repair in the cell cycle and discusses th...

Residual DNA double strand breaks correlates with excess acute toxicity from radiotherapy

Introduction: A high risk for development of severe side effects after radiotherapy may be correlated with high cellular radiosensitivity. To enhance radiation therapy efficiency a fast and reliable in-vitro test is desirable to identify radiosensitive patients. The aim of present study was to identify the mechanism of radiation induced DNA double-strand breaks (DSBs) and DSB r...