This is the first study that shows the 3D structure of a molecular complex found in the bacteria Mycobacterium tuberculosis that repairs DNA damage. According to the biochemical data, this reflects a stage of the search for compatible microhomologies. This is the process of seeking non complementary extremes of DNA that would never link under normal conditions, known as non-homologous end joining (NHEJ). Among the Spanish participating researchers are Dr. Raquel Juárez Santos, and Dr. Angel J. Picher Serantes.
The double strand breaking of DNA is considered the most lethal kind of damage for our genome, since an error in its repair potentially represents cell death or tumour growth. Non-homologous end joining is a repair process for the double strand breaking of DNA which can operate at any stage of the cellular cycle, and it is essential in maintaining the genome stability in mammals. The process uses a combination of proteins responsible for the protection and maintenance of the proximity of the ends as well as all the actions necessary to repair the rupture. As an analogy, NHEJ operates like an adhesive kit that cleans the damaged area, fills the missing parts, and glues together the loose ends, even if is inevitable that some nucleotides are changed or lost in the process. A potential hazard of this mechanism is simultaneous ruptures, since it is possible that the strands are confused and the wrong strands are glued together, and such a translocation could activate an oncogene.
This study, published in Science magazine, identifies the structural bases of the NHEJ process in the DNA of the bacteria Mycobacterium tuberculosis, and shows for the first time the 3D structure of a NHEJ repairing complex. Up until now, there was little information about the different processing activities that occur in sequential coordination during the NHEJ, either about the independent proteins of mammals, or the different parts of the same protein like in bacteria. The union of the extremities shown in the 3D structure and described in this study, shows the stage of alignment of the ends, prior to the processing by the activity of nuclease (DNA cleaver), polymerase (DNA synthesis) and ligase (DNA binding), all carried out by the enzyme LigD (DNA repair) in the case of bacteria. This study can be extrapolated to the NHEJ of mammals.
From a more applied point of view, this analysis identifies the polymerization of the bacterial LigD as a possible target to hamper the repair process of double strand breaks in these organisms. It has been proven that the NHEJ is a source of genetic variability in bacteria, necessary for their adaptation and survival in genotoxic (toxic for DNA) environments. The selective elimination of this process could have applications such as treatments that avoid the generation of antibiotic resistant bacteria.
Oficina de Cultura Científica | alfa
Meadows beat out shrubs when it comes to storing carbon
23.11.2017 | Norwegian University of Science and Technology
Migrating Cells: Folds in the cell membrane supply material for necessary blebs
23.11.2017 | Westfälische Wilhelms-Universität Münster
Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
23.11.2017 | Information Technology
23.11.2017 | Physics and Astronomy
23.11.2017 | Life Sciences