The genetic stability of living cells is continually threatened by endogenous reactive oxygen species and other genotoxic molecules. Of particular threat are the thousands of single-strand breaks that arise in each cell every day. If left unrepaired, such breaks can give rise to potentially clastogenic or lethal chromosomal double-strand breaks. This article summarizes our current understanding...

Condensin I is important for chromosome organization and segregation in mitosis. We previously showed that condensin I also interacts with PARP1 in response to DNA damage and plays a role in single-strand break repair. However, whether condensin I physically associates with DNA damage sites and how PARP1 may contribute to this process were unclear. We found that condensin I is preferentially re...

DNA nicks are the most common form of DNA damage, and if unrepaired can give rise to genomic instability. In human cells, nicks are efficiently repaired via the single-strand break repair pathway, but relatively little is known about the fate of nicks not processed by that pathway. Here we show that homology-directed repair (HDR) at nicks occurs via a mechanism distinct from HDR at double-stran...

A Monte Carlo simulated annealing (MCSA) algorithm was used to generate the conformations of local regions in bovine pancreatic trypsin inhibitor (BPTI) starting from random initial conformations. In the approach explored, only the conformation of the segment is computed; the rest of the protein is fixed in the known native conformation. Rather than follow a single simulation exhaustively, comp...

With China's rapid economic development, the reduction in arable land has emerged as one of the most prominent problems in the nation. The long-term dynamic monitoring of arable land quality is important for protecting arable land resources. An efficient practice is to select optimal sample points while obtaining accurate predictions. To this end, the selection of effective points from a dense ...

Abbreviations: CPD: Cyclobutane Pyrimidine Diner; DLR: German Aerospace Center; ds-break: Double Strand Break; EST: Experiment Sequence Test; EVT: Experiment Verification Test; ISS: International Space Station; IWF: Institut für Weltraumforschung; LEO: Low Earth’s Orbit; OD: Optical density [log(I0/I)]; PCR: Polymerase Chain Reaction; PLC: Payload Computer; RGB: Research Group for Biophysics; s...

Double strand breaks (DSBs) can be repaired by homology independent nonhomologous end joining (NHEJ) pathways involving proteins such as Ku70/80, DNAPKcs, Xrcc4/Ligase 4, and the Mre11/Rad50/Nbs1 (MRN) complex. DSBs can also be repaired by homology-dependent pathways (HDR), in which the MRN and CtIP nucleases produce single strand ends that engage homologous sequences either by strand invasion ...

Single-strand break repair and genetic disease. DNA single-strand break repair SSBR is critical for the survival and. The association of human genetic disorders with defects in the DNA.encounter DNA single-strand breaks or other types of lesion. An inability to respond properly to, or to repair, DNA damage leads to genetic instability. Developmental disorders, Werner syndrome WS and Bloom syndr...