A complex of proteins in the bacterium E.coli that plays a critical role in defending the microbe from viruses and other invaders has been discovered to have the shape of a seahorse by researchers with the U.S Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab). This discovery holds far more implications for your own health than you might think.
In its never-ending battle to protect you from infections by bacteria, viruses, toxins and other invasive elements, your immune system has an important ally many allies in fact. By the time you reach adulthood, some 90-percent of the cells in your body are microbial. These microbes collectively known as the microbiome play a critical role in preserving the health of their human host.
"Perturbations of the human microbiome by viral and other infections can disrupt important symbioses and open the door to invasions by human pathogens," says Blake Wiedenheft, a biochemist with Berkeley Lab and the University of California (UC) Berkeley. "By understanding the mechanisms behind microbial immune systems, we can better understand how they are similar and where they are different from the human immune system."
Wiedenheft is part of a team of researchers, led by biochemist Jennifer Doudna, a leading authority on RNA molecular structures, and biophysicist Eva Nogales, an expert on electron microscopy and image analysis, that has provided the first sub-nanometer look at a central player in the microbial immune system. Through a combination of cryo-electron microscopy and three-dimensional image reconstruction, they have determined the structure of a protein complex called "Cascade," that acts as a surveillance system for detecting and inactivating the nucleic acid of invading pathogens.
Doudna and Nogales are the corresponding authors and Wiedenheft and Gabriel Lander are the lead authors of a paper describing this research in the journal Nature. The
|Contact: Lynn Yarris|
DOE/Lawrence Berkeley National Laboratory