Capybara gut holds valuable enzymes for biotechnology

Study elucidates unprecedented processes of herbivore metabolism involved in the efficient degradation of plant fibers

A group of researchers from the Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), an organization supervised by the Brazilian Ministry of Science, Technology and Innovations (MCTI), has published in the journal Nature Communications a study that explores some of the most modern resources of current science to reveal unprecedented and valuable details of the capybara’s digestive process.

The capybara, the largest rodent on the planet, is known for its ability to degrade very efficiently the biomass it consumes, but the details of the animal’s microbiota metabolism that contribute to this characteristic have not yet been elucidated. Researcher Mario Murakami recalls that, in Brazil, this animal is used to eating sugarcane. “Since Brazilian biodiversity is an invaluable source of biotechnological solutions, our hypothesis was that the microorganisms inhabiting capybaras’ intestines have, throughout evolution, developed highly effective molecular strategies for the degradation and use of this biomass of great industrial and economic importance. And that was demonstrated in our study.”

“Population and molecular inventory” of the gut microbiome

The meticulous and unprecedented work started with a complete survey of the bacteria present in the capybara’s intestine, in addition to the expressed genes and metabolites produced from plant fibers. To understand the processes of depolymerization of lignocellulosic fibers and the efficient transformation of sugars into energy, a vast combination of techniques, methodologies and resources, including synchrotron light at the MX2 and SAXS1 beamlines of the Brazilian Synchrotron Light Laboratory (LNLS), was required, from the population scale of microorganisms to the atomic and molecular level of enzymes.

Read more the the LNLS website

New detector accelerates protein crystallography

In Feburary a new detector was installed at one of the three MX beamlines at HZB.

Compared to the old detector the new one is better, faster and more sensitive. It allows to acquire complete data sets of complex proteins within a very short time.

Proteins consist of thousands of building blocks that can form complex architectures with folded or entangled regions. However, their shape plays a decisive role in the function of the protein in the organism. Using macromolecular crystallography at BESSY II, it is possible to decipher the architecture of protein molecules. For this purpose, tiny protein crystals are irradiated with X-ray light from the synchrotron source BESSY II. From the obtained diffraction patterns, the morphology of the molecules can be calculated.

>Read more on the BESSY II at HZB website

Image: 60s on the new detector were sufficient to obtain the electron density of the PETase enzyme.
Credit: HZB

Structure and functional binding epitopes of VISTA

V-domain Ig Suppressor of T-cell Activation (VISTA) is an immune checkpoint protein involved in the regulation of T cell activity. Checkpoint proteins are overexpressed by cancer cells or surrounding immune cells and prevent anti-tumor activity by co-opting natural regulation mechanisms to escape immune clearance. Compared to healthy tissues, VISTA is upregulated on tumor infiltrating leukocytes, including high expression on myeloid-derived suppressor cells (MDSCs). Through VISTA signaling, these inhibitory immune cells prevent effective antigen presentation and indirectly promote tumor growth. VISTA is implicated in a number of human cancers including skin (melanoma), prostate, colon, pancreatic, ovarian, endome­trial, and non-small cell lung. VISTA is a known member of the B7 protein family but the mechanism of action is still unclear as VISTA has been shown to function as both a ligand1,2 and a receptor3.  In the model of VISTA as a receptor, the proposed ligand of interaction is V-set and immunoglobulin domain containing 3 (VSIG3)4,5.

>Read more on the SSRL website

Image: Structure of human VISTA with extended C-C’ loop (blue), mapped VSTB/VSIG3 binding epitope (red), and disulfide bonds (yellow).

New sample holder for protein crystallography

An HZB research team has developed a novel sample holder that considerably facilitates the preparation of protein crystals for structural analysis.

A short video by the team shows how proteins in solution can be crystallised directly onto the new sample holders themselves, then analysed using the MX beamlines at BESSY II. A patent has already been granted and a manufacturer found. Proteins are huge molecules that often have complex three-dimensional structure and morphology that can include side chains, folds, and twists. This three-dimensional shape is often the determining factor of their function in organisms. It is therefore important to understand the structure of proteins both for fundamental research in biology and for the development of new drugs. To accomplish this, proteins are first precipitated from solution as tiny crystals, then analysed using facilities such as the MX beamlines at BESSY II in order to generate a computer image of the macromolecular structure from the data.

>Read more on the BESSY II at HZB website

Image: Up to three indivudal drops may be placed onto the sample holder.
Credit: HZB

A new generation of anti-malaria drugs

Malaria is endemic to large areas of Africa, Asia and South America and annually kills more than 400,000 people, a majority of whom are children under age 5, with hundreds of millions of new infections every year. Although artemisinin-based drug combinations are available to treat malaria, reports from Southeast Asia of treatment failures are raising concerns about drug resistance spreading to Africa. Fortunately, there is hope on the horizon because there are several new antimalarial drug candidates undergoing clinical testing as well as other promising drug targets that are under investigation.
An international research team has for the first time determined the atomic structure of a protein kinase called PKG in Plasmodium parasites that cause malaria—a finding that potentially will help create a new generation of anti-malarial drugs and advance fundamental research. PKG[i] plays essential roles in the developmental stages of the parasite’s complex life cycle, so understanding its structure is key to developing malaria-fighting therapies that specifically target PKG and not other human enzymes, according to researcher Dr. Charles Calmettes.

>Read more on the Canadian Light Source website

Image: PKG crystal.

Potassium hunting on protein factories

Amazing insights into the location of elusive potassium ions on bacterial ribosomes

Groundbreaking research at the new long-wavelength macromolecular crystallography beamline (I23) at Diamond Light Source has for the first time demonstrated the location of potassium ions in bacterial ribosomes. Ribosomes are the protein factories of cells and although they are vital for life, little was known of the sites of metal ions that are crucial for their structure and function. The work recently published in Nature Communications showcases the fantastic applications of the I23 beamline and sheds light on the important role of potassium ions.

>Read more on the Diamond Light Source website

Image: (extract, full image here) 70S ribosome elongation complex (potassium atoms rendered as green spheres).

Doubling the DNA alphabet

Implications for life in the universe and DNA storage

Life on Earth is dictated by the DNA alphabet comprised of only four DNA bases or letters: A, T, G and C. It has long been of interest to understand whether there is something very special about the four letters that comprise DNA and whether this is the only code that could support life. At a basic level, this question can be addressed by examining an expanded alphabet and determining the properties of DNA including additional synthetic letters. This study impacts our current understanding of terrestrial DNA and suggests that extraterrestrial life forms could have evolved using a different genetic code than found here on Earth. The work has immediate applications in synthetic biology for the creation of new molecules and greatly expands the ability to store information in DNA.

Now, in breakthrough work, funded by NASA, NSF and NIGMS, Dr. Steven Benner at the Foundation for Applied Molecular Evolution, in collaboration with Dr. Millie Georgiadis at the Indiana University School of Medicine, and colleagues at biotechnology companies and other universities, have provided evidence that the standard DNA code can be expanded to include eight letters forming “hachimoji DNA” (“hachi” eight and “moji” letter in Japanese) using four novel synthetic nucleobases (B, S, P and Z) in addition to A, T, C and G and still retain critical features of natural DNA1,2. Structurally, hachimoji DNA can adopt a standard double helical form of DNA and retain Watson-Crick complementary base pairing, which allows the expanded DNA to be faithfully replicated and transcribed by polymerases to produce hachimoji DNA copies and hachimoji RNA. These properties are essential for a genetic system that can support life.

>Read more on the Stanford Synchrotron Radiation Lightsource (SSRL) at SLAC website

Image: Crystal structure of a double helix built from eight hachimoji building blocks, G (green), A (red), C (dark blue), T (yellow), B (cyan), S (pink), P (purple), and Z (orange). The first four building blocks are found in human DNA; the last four are synthetic, and possibly present in alien life. Each strand of the double helix has the sequence CTTAPCBTASGZTAAG. Notable is the geometric regularity of the pairs, a regularity that is needed for evolution.

Structural insights into tiny bacterial harpoons

Bacteria produce complex nano-harpoons on their cell surface. One of their functions is to harpoon and inject toxins into cells that are close by. Producing such a complex weapon requires lots of different moving components that scientists are still trying to understand. Researchers from the University of Sheffield have been using some of Diamond’s crystallography beamlines to understand a particularly enigmatic piece of this tiny puzzle. The team led by David Rice and Mark Thomas worked on a protein component of the harpoon called TssA which they already knew was an integral piece of the machinery. However, unlike the other components of the harpoon, there are distinct variants of the TssA protein that contain radically different amino acid sequences at one end of the protein. The team showed that the structures of the variable region of two different TssA subunits were completely unrelated and they could assemble into distinctly different multisubunit complexes in terms of their size and geometry. This begged the question as to how different bacteria could use this protein with different structures to produce a harpoon with the same function across all species. They found that despite these differences, there was a very specific conserved region at the other end of the protein. They hypothesise that the conserved region is the part that does the work and helps the harpoon to function whereas the variable region acts as a scaffold. They used I02, I03 and I24 in their study and plan to do follow up work using X-ray crystallography and Cryo-EM such as those at the eBIC centre at Diamond. The research was published in Nature Communications.

>Read more on the Diamond Light Source website

Image: Macromolecular Crystallography (MX) at Diamond reveals the shape and arrangement of biological molecules at atomic resolution, knowledge of which provides a highly accurate insight into function. 

First users on VMXm

First users from the University of Southampton investigated proteins involved in nutrient uptake of photosynthetic or cyanobacteria to understand how these phytoplankton thrive under scarce nutrient conditions.

The work has immense global significance for biofuels production and biotechnology. This beamline marks the completion of Diamond’s original Phase III funding on time and within budget.

First users have now been welcomed by Diamond Light Source, the UK’s national synchrotron light source on its new VMXm beamline. The Versatile Macromolecular Crystallography micro/nanofocus (VMXm) beamline becomes the 32nd operational beamline to open its doors to users, completing the portfolio of seven beamlines dedicated to macromolecular crystallography.
The unique VMXm beamline represents a significant landmark for Diamond. It is a specialist tuneable micro/nanofocus macromolecular crystallography (MX) beamline, with an X-ray beam size of less than 0.5 microns, allowing even the tiniest of samples to be analysed. Integrated into the ‘in vacuum’ sample environment is a scanning electron microscope, making VMXm a hybrid X-ray/cryoEM instrument for detecting and measuring data from nanocrystals. VMXm is aimed at research applications where the production of significant quantities of protein and crystals is difficult.

>Read more on the Diamond Light Source website

Image: Principal Beamline Scientist Dr Gwyndaf Evans with his team Dr Jose Trincao, Dr Anna Warren, Dr Emma Beale and Dr Adam Crawshaw. First users – Dr Ivo Tews from Biological Sciences at the University of Southampton and joint Diamond-Southampton PhD student Rachel Bolton investigating proteins involved in nutrient uptake of photosynthetic or cyanobacteria.

Snaphot of molecular mechanism at work in lethal virus

X-ray crystallography at the Australian Synchrotron contributed to major research findings.

Data collected on the macromolecular crystallography beamlines at the Australian Synchrotron has contributed to major research findings on two deadly viruses, Hendra and Nipah, found in Australia, Asia and Africa. The viruses can be transmitted to humans not directly by the bat which is the natural carrier but by an infected animal like horses or pigs.

Beamline scientist, Dr David Aragao (pictured above), a co-author on the paper in Nature Communications, said that obtaining a clear motion picture of key biological process at the molecular level of viruses is often not available with current biomedical techniques.
“However, using X-ray crystallography from data collected on both MX1 and MX2 beamlines at the Australian Synchrotron, we were able to obtain  8  ‘photograph-like’ snapshots of the molecular process that allows the Hendra and Nipah virus to replicate.“

Two authors of the paper, PhD students Kate Smith and Sofiya Tsimbalyuk, who are co-supervised by Aragao and his collaborator Professor of Biochemistry Jade Forwood of the Graham Centre for Agricultural Innovation Charles Sturt University, used the Synchrotron extensively collecting multiple data sets that required extensive refinements over two years to isolate the mechanism of interest.

>Read more on the Australian Synchrotron website

Image: Beamline scientist, Dr David Aragao.

New high-precision instrument enables rapid measurements of protein crystals

A team of scientists and engineers at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have developed a new scientific instrument that enables ultra-precise and high-speed characterization of protein crystals at the National Synchrotron Light Source II (NSLS-II)—a DOE Office of Science User Facility at Brookhaven, which generates high energy x-rays that can be harnessed to probe the protein crystals. Called the FastForward MX goniometer, this advanced instrument will significantly increase the efficiency of protein crystallography by reducing the run time of experiments from hours to minutes.

Protein crystallography is an essential research technique that uses x-ray diffraction for uncovering the 3D structures of proteins and other complex biological molecules, and understanding their function within our cells. Using this knowledge about the basic structure of life, scientists can advance drug design, improve medical treatments, and unravel other environmental and biochemical processes governing our everyday lives.

>Read more on the NSLS-II website

Image: Yuan Gao, Wuxian Shi, Evgeny Nazaretski, Stuart Myers, Weihe Xu and, Martin Fuchs designed and implemented the new goniometer scanner system for ultra-fast and efficient serial protein crystallography at the Frontier Microfocusing Macromolecular Crystallography (FMX) beamline at the National Synchrotron Light Source II.

The proteins that bind

Researchers reveal the structure of a protein that helps bacteria aggregate

Serine-rich repeat proteins (SRRPs), which help bacteria attach to surfaces, have been structurally characterised in pathogenic bacteria but not in beneficial bacteria such as those present in the gut. Dr Nathalie Juge’s team at the Quadram Institute Bioscience has previously identified SRRP as a main adhesin in Lactobacillus reuteri strains from pigs and mice. Now, together with colleagues at the University of East Anglia, they have described the structure and activity of the binding region of L. reuteri SRRPs in a paper published in PNAS. Using the Macromolecular Crystallography beamlines (I03 and I04) at Diamond Light Source, they discovered that the structure of these proteins is unique among characterised SRRPs and is surprisingly similar to pectin degrading enzymes. Molecular simulations and binding experiments revealed a pH-dependent binding to pectin and to proteins from the epithelium known as mucins. Altogether, these findings shed light on the activity of a key protein in these bacteria and may help guide the development of more targeted probiotic interventions.

>Read more on the Diamond Light Source website

Figure: (Left) Cartoon representation of crystal structures of the binding region of SRRP53608. (Right) Cartoon representation of crystal structures of the binding region of SRRP100-23. The N-terminus is shown with blue balls and the C-terminus is shown with red balls.

Solution to plastic pollution on the horizon

Engineering a unique plastic-degrading enzyme

The inner workings of a recently discovered bacterium with a fascinating ability to use plastic as an energy source have been recently revealed in PNAS. The world’s unique Long-Wavelength Macromolecular Crystallography (MX) beamline here at Diamond Light Source was used to successfully solve the structure of the bacterial enzyme responsible for chopping up the plastic. This newly evolved enzyme could be the key to tackling the worldwide problem of plastic waste.

Plastic pollution is a global threat that desperately needs addressing. Plastics are rarely biodegradable and they can remain in the environment for centuries. One of the most abundant plastics that contributes hugely to this dire situation is poly(ethylene terephthalate) (PET).

PET is used largely in textiles, where it is commonly referred to as polyester, but it is also used as packaging for liquids and foodstuffs. In fact, PET’s excellent water-repellent properties led to it being the plastic of choice for soft drink bottles. However, once plastic bottles are discarded in the environment the water resistance of PET means that they are highly resistant to natural biodegradation. PET bottles can linger for hundreds of years and plastic waste like this will accumulate over time unless a solution is found to degrade them.

A recent breakthrough came in the discovery of a unique bacterium, Ideonella sakaiensis 201-F6, which was found feeding on waste from an industrial PET recycling facility. PET has only been widely used since the 1970s, so the bacterium had evolved at breakneck speed to be able to take advantage of the new food source.

The bacterium had the amazing ability to degrade PET and use it to provide carbon for energy. Central to this ability was the production of a PET-digesting enzyme, known as PETase.

>Read more on the Diamond Light Source website


Hijacker parasite blocked from infiltrating blood

A major international collaboration led by Melbourne researchers has discovered that the world’s most widespread malaria parasite infects humans by hijacking a protein the body cannot live without.

The researchers were then able to successfully develop antibodies that disabled the parasite from carrying out this activity.
The study, led by the Walter and Eliza Hall Institute’s Associate Professor Wai-Hong Tham and Dr Jakub Gruszczyk, found that the deadly malaria parasite Plasmodium vivax (P. vivax) causes infection through latching onto the human transferrin receptor protein, which is crucial for iron delivery into the body’s young red blood cells.

Published today in Science, the discovery has solved a mystery that researchers have been grappling with for decades.
The MX and SAXS beamline staff at the Australian Synchrotron assisted with data collection.

Associate Professor Tham, who is also a HHMI-Wellcome International Research Scholar, said the collective efforts of teams from Australia, New Zealand, Singapore, Thailand, United Kingdom, United States, Brazil and Germany had brought the world closer to a potential effective vaccine against P.vivax malaria.

>Read more on the Australian Synchrotron website