All plants and animals are susceptible to viral infections. But did you know that’s also true for bacteria? They get nailed by viruses called bacteriophages, and there are thousands of them in nature including this one that resembles a lunar lander: bacteriophage T4 (left panel). It’s a popular model organism that researchers have studied for nearly a century, helping them over the years to learn more about biochemistry, genetics, and molecular biology .
The bacteriophage T4 infects the bacterium Escherichia coli, which normally inhabits the gastrointestinal tract of humans. T4’s invasion starts by touching down on the bacterial cell wall and injecting viral DNA through its tube-like tail (purple) into the cell. A DNA “packaging machine” (middle and right panels) between the bacteriophage’s “head” and “tail” (green, yellow, blue spikes) keeps the double-stranded DNA (middle panel, red) at the ready. All the vivid colors you see in the images help to distinguish between the various proteins or protein subunits that make up the intricate structure of the bacteriophage and its DNA packaging machine.
Posted In: Snapshots of Life
Tags: bacteria, bacteriophage, cancer, Chimera Visualization Software, cryo-electron microscopy, cryo-EM, E. coli, Escherichia coli, FASEB Bioart 2017, HIV, structural biology, T4 bacteriophage, virus, x-ray crystallography
Many of us think of soil as lifeless dirt. But, in fact, soil is teeming with a rich array of life: microbial life. And some of those tiny, dirt-dwelling microorganisms—bacteria that produce antibiotic compounds that are highly toxic to other bacteria—may provide us with valuable leads for developing the new drugs we so urgently need to fight antibiotic-resistant infections.
Recently, NIH-funded researchers discovered a new class of antibiotics, called malacidins, by analyzing the DNA of the bacteria living in more than 2,000 soil samples, including many sent by citizen scientists living all across the United States . While more work is needed before malacidins can be tried in humans, the compounds successfully killed several types of multidrug-resistant bacteria in laboratory tests. Most impressive was the ability of malacadins to wipe out methicillin-resistant Staphylococcus aureus (MRSA) skin infections in rats. Often referred to as a “super bug,” MRSA threatens the lives of tens of thousands of Americans each year .
Tags: antibiotic resistance, antibiotic treatment, antibiotics, bacteria, calcium-dependent antibiotics, citizen science, DNA, Drugs from Dirt, malacidins, MRSA, multi-drug resistance, multidrug resistant bacteria, soil, soil-dwelling bacteria, Staphylococcus aureus, Streptomyces albus, super bug
The recipes for life, going back billions of years to the earliest single-celled organisms, are encoded in a DNA alphabet of just four letters. But is four as high as the DNA code can go? Or, as researchers have long wondered, is it chemically and biologically possible to expand the DNA code by a couple of letters?
A team of NIH-funded researchers is now answering these provocative questions. The researchers recently engineered a semi-synthetic bacterium containing DNA with six letters, including two extra nucleotides [1, 2]. Now, in a report published in Nature, they’ve taken the next critical step . They show that bacteria, like those in the photo, are not only capable of reliably passing on to the next generation a DNA code of six letters, they can use that expanded genetic information to produce novel proteins unlike any found in nature.
Tags: amino acids, bacteria, bioengineering, codon, DNA, DNA alphabet, DNA code, E. coli, expanded DNA code, genetic code, green fluorescent protein, nucleotides, protein, protein therapeutics, transfer RNA
If you have a smartphone, you’ve probably used it to record a video or two. But could you use it to produce a video that explains a complex scientific topic in 2 minutes or less? That was the challenge posed by the RCSB Protein Data Bank last spring to high school students across the nation. And the winning result is the video that you see above!
This year’s contest, which asked students to provide a molecular view of diabetes treatment and management, attracted 53 submissions from schools from coast to coast. The winning team—Andrew Ma, George Song, and Anirudh Srikanth—created their video as their final project for their advanced placement (AP) biology class at West Windsor-Plainsboro High School South, Princeton Junction, NJ.
Tags: 2017 RCSB Protein Data Bank Video Challenge for High School Students, AP Biology, bacteria, biology, diabetes, genetic engineering, high school, insulin, protein structure, RCSB Protein Data Bank, smartphone, STEM, structural biology, video