In 2020, paleontologists described an ancient species, Oculudentavis khaungraae, based on a tiny skull trapped in a piece of Cretaceous-period amber from...
Astronomers using NASA’s Interstellar Boundary Explorer (IBEX) satellite have mapped the boundary of the heliosphere, the vast region of space surrounding...
Dendrohyrax interfluvialis lives in the wet and dry forests that lie between the two rivers in coastal regions of southeastern Ghana, southern Togo and...
A team of researchers from Thomas Jefferson University, Philadelphia, the University of Southern California, the Beckman Research Institute of the City...
A team of archaeologists from the Israel Antiquities Authority (IAA) has found an unbroken chicken egg in an Islamic-period cesspit at the archaeological...
Professional astronomers and citizen scientists from the NASA-funded Planet Hunters TESS project have discovered a two-planet system around the bright...
A giant star called VVV-WIT-08 exhibited a smooth, eclipse-like drop in brightness to a depth of 97% in 2012; minimum brightness occurred in April 2012...
Paleoclimatologists have precisely reconstructed monthly sea surface temperatures at around 50 °N latitude from fossil shells of bivalve mollusks that...
Physicists from the LHCb Collaboration at CERN have proved that a subatomic particle called the charm meson can switch into its antiparticle and back again....
Microscopic multicellular animals called bdelloid rotifers are known for their ability to survive extremely low temperatures. They had been reported to...
A new study, published this month in the Proceedings of the National Academy of Sciences, shows that within the same society, adolescent students who specifically...
Archaeologists have uncovered the remains of a 2,000-year-old Roman basilica complex in the Tel Ashkelon National Park, Israel.
Aerial view of the Roman...
A team of researchers from the Carnegie Institution for Science, RMIT University and the Australian National University has synthesized a new form of silicon...
Two major problems that limit the resolution and interpretation of electron microscopy images are lens aberrations and multiple scattering. Cornell University’s...
In a new study published in the journal Cell Metabolism, researchers took a closer look at the functions of different sensory neurons in the control center...
An acoustic amplifier developed by Sandia National Laboratories researchers measures 0.5 mm2 (0.0008 square inches), and is more than 10 times more effective...
![Ternary structure of Polθ on a DNA/RNA primer-template: (A) Polθ polymerase; (B) DNA/RNA extension by Polθ and PolθΔL; (C) structure of Polθ:DNA/RNA:ddGTP; (D) superposition of Polθ:DNA/RNA (marine) and Polθ:DNA/DNA (orange, 4x0q); the fingers and thumb subdomains undergo reconfiguration; (E) superposition of Polθ:DNA/RNA (marine) and Polθ:DNA/DNA (orange, 4x0q) highlighting a 12-Å shift of K2181 (blue box; thumb) and a 4.4-Å shift of E2246 (gray box; palm); (F) superposition of nucleic acids and ddGTP from Polθ:DNA/RNA:ddGTP and Polθ:DNA/DNA:ddGTP structures; (G) top: electron density of ddGTP and 3′ primer terminus in Polθ:DNA/RNA structure; bottom: zoomed-in image of the superposition of active sites, illustrating a different conformation of ddGTP in the Polθ:DNA/RNA (blue) and Polθ:DNA/DNA (salmon) complexes; (H) interactions between ribose 2’-hydroxyl groups of the RNA template and residues in the Polθ:DNA/RNA structure; red dashed lines, hydrogen bonds; (I) DNA/RNA used for cocrystallization with Polθ and ddGTP (top); strong electron density is present for four base pairs [nucleotides located at positions 2 to 5 (underlined) of the DNA/RNA] and two base pairs resulting from an incorporated ddGMP (2’,3’ dideoxyguanosine monophosphate) (green; position 1) and a bound unincorporated ddGTP (red; position 0) in the active site (top); interactions between Polθ and nucleic acids in Polθ:DNA/RNA:ddGTP (bottom); interactions between residues and phosphate backbone, sugar oxygen, or nucleobase are shown in blue, yellow, and green, respectively; hydrogen bonds between Polθ and ribose 2’-hydroxyl groups are indicated (boxed residues); (J) interactions between Polθ and nucleic acids in Polθ:DNA/DNA:ddGTP (4x0q); color scheme identical to (I). Image credit: Chandramouly et al., doi: 10.1126/sciadv.abf1771.](https://cdn.sci.news/images/2021/06/image_9759-Polymerase-Theta-195x110.jpg)
