Single-strand interruptions in replicating chromosomes cause double-strand breaks

Single-strand interruptions in replicating chromosomes cause double-strand breaks.

Replication-dependent chromosomal breakage suggests that replication forks occasionally run into nicks in template DNA and collapse, generating double-strand ends. To model replication fork collapse in vivo, I constructed phage lambda chromosomes carrying the nicking site of M13 bacteriophage and infected with these substrates Escherichia coli cells, producing M13 nicking enzyme. I detected dou...

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...

Double-strand breaks and tumorigenesis.

The establishment of connections between biochemical defects and clinical disease is a major goal of modern molecular genetics. In this review, we examine the current literature that relates defects in the two major DNA double-strand-break repair pathways--homologous recombination and nonhomologous end-joining--with the development of human tumors. Although definitive proof has yet to be obtain...

Proteins pinpoint double strand breaks

Combining green fluorescent protein with a protein that only binds to double strand breaks in DNA allows these breaks-which are an important form of DNA damage-to be detected with high efficiency in living bacteria.

DNA Double-Strand Breaks Relieve