The DNA damage response kinase ataxia telangiectasia and Rad3-related (ATR) coordinates much of the cellular response to replication stress. The exact mechanisms by which ATR regulates DNA synthesis in conditions of replication stress are largely unknown, but this activity is critical for the viability and proliferation of cancer cells, making ATR a potential therapeutic target. Here we use sel...

Stalled replication forks are a critical problem for the cell because they can lead to complex genome rearrangements that underlie cell death and disease. Processes such as DNA damage tolerance and replication fork reversal protect stalled forks from these events. A central mediator of these DNA damage responses in humans is the Rad5-related DNA translocase, HLTF. Here, we present biochemical a...

The active center clefts of RNA polymerase (RNAP) from the archaeon Pyrococcus furiosus (Pfu) and of yeast RNAP II are nearly identical, including four protruding loops, the lid, rudder, fork 1 and fork 2. Here we present a structure-function analysis of recombinant Pfu RNAP variants lacking these cleft loops, and analyze the function of each loop at different stages of the transcription cycle....

To identify the products of chromosome replication (termed sister chromatids) from S-phase through M-phase of the cell cycle, each sister pair becomes tethered together by specialized protein complexes termed cohesins. To participate in sister tethering reactions, chromatin-bound cohesins become modified by establishment factors that function during S-phase and bind to DNA replication-fork comp...

In this paper a strong relation is demonstrated between fork algebras and quasi-projective relation algebras. With the help of the representation theorem of quasi-projective relation algebras, a short proof is given for the representation theorem of fork algebras. Fork algebras, due to their expressive power and applicability in computing science, have been intensively studied in the last four ...

Glacial deposits on the north slope of the Uinta Mountains were investigated through map and air photo interpretation combined with fi eld mapping. Deposits representing the Smiths Fork (local Pinedale equivalent), Blacks Fork (Bull Lake equivalent) and pre-Blacks Fork Glaciations are present in the form of terminal and lateral moraines, ground moraine, and outwash valley trains. Nineteen separ...

The Shenandoah River (VA, USA), the largest tributary of the Potomac River (MD, USA) and an important source of drinking water, has been the site of extensive fish kills since 2004. Previous investigations indicate environmental stressors may be adversely modulating the immune system of smallmouth bass (Micropterus dolomieu) and other species. Anterior kidney (AK) tissue, the major site of bloo...

The stalling of DNA replication forks that occurs as a consequence of encountering DNA damage is a critical problem for cells. RecG protein is involved in the processing of stalled replication forks, and acts by reversing the fork past the damage to create a four-way junction that allows template switching and lesion bypass. We have determined the crystal structure of RecG bound to a DNA substr...

The eukaryotic cell replicates its chromosomal DNA with almost absolute fidelity in the course of every cell cycle. This accomplishment is remarkable considering that the conditions for DNA replication are rarely ideal. The replication machinery encounters a variety of obstacles on the chromosome, including damaged template DNA. In addition, a number of chromosome regions are considered to be d...