SEP 15, 2017 7:29 AM PDT

New Kind of Enzyme Helps Bacteria Infect Hosts

WRITTEN BY: Carmen Leitch
A new type of enzyme has been discovered in hundreds of bacterial species, and researchers say it helps reveal how bacteria invade organisms. Reporting in Nature Communications, this work may help us understand the mechanisms that underlie bacterial infections, and shows how bacteria use special appendages called flagella for more than just movement.
 
This is a a transmission electron microscope (TEM) image of isolated flagella from Clostridium haemolyticum. Black dots indicates the location of the newly discovered enzyme. / Credit: University of Waterloo
 
Led by Andrew Doxey, a Professor of Biology at the University of Waterloo, investigators identified a new kind of flagella. These whip-like appendages are attached to the outside of bacteria and have been thought to be used exclusively for motility. This work shows that another kind of flagellum acts as an enzyme, breaking down proteins that are in the bacteria’s environment. New tools in bioinformatics, which merges biology with computer science, enabled the scientists to make their discovery.
 
"It is an exciting time for bioinformatics right now. We have thousands of genomes available to us, and most of them are unexplored. It's amazing that we can discover new biology by using a computer alone," noted Doxey. "What we found, in this case, is that many bacteria have repurposed their flagella to function as protein-degrading enzymes. There are thousands of these enzymes, making this potentially one of the largest enzyme structures known."
 
You can learn more about bacterial flagella, filaments made up of thousands of proteins, from the video. Although there are structural differences in flagella, the majority seem to help move bacteria around, and can also help bind bacteria to host cells. This new work shows how they digest bonds between cells in tissues.
 

 

"We think that these enzymatic flagella may help some bacteria degrade and move through viscous environments. Interestingly, scientists have tried engineering flagella with this functionality before, but until now, we didn't know that nature already did this," explained Doxey, who is also a member of the Centre for Bioengineering and Biotechnology at Waterloo.
 
This work assessed enzymatic flagella that are found in the pathogen Clostridium haemolyticum, which can cause deadly infections in sheep and cows. There are several flagella on each one of these bacterial cells, and they were isolated by the researchers. It was found that these flagella can break down proteins found in the liver of cows, which is exactly where the pathogen initiates an infection.
 
Bacteria in the human gut also have these types of enzymes, the investigators determined. Additional work will be required before it is known whether these have harmful or beneficial functions in humans.
 
This discovery may also be useful to humans if they can be harnessed for our purposes. One potential use is for the destruction of harmful bacterial biofilms. These highly pathogenic colonies of microbes can form in troublesome places, including medical equipment, and many researchers are looking for ways to target and destroy them.
 
About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
MAR 24, 2020
Cell & Molecular Biology
MAR 24, 2020
Certain Drugs May Raise the Risk of a Severe COVID-19 Infection
ACEIs and ARBs may make coronavirus infections worse, which can help explain why older adults are faring so much worse.
MAR 26, 2020
Microbiology
MAR 26, 2020
US Now Leads the World in Coronavirus Cases
In the United States, there have been 83,836 confirmed cases of COVID-19, and over 529,000 worldwide.
MAY 05, 2020
Microbiology
MAY 05, 2020
How a Microbe May Help Stop the Spread of Malaria
Scientists have discovered a bacterium that lives in mosquitoes around Lake Victoria, and appears to block malaria.
MAY 10, 2020
Microbiology
MAY 10, 2020
We Still Don't Know Why Rat Hepatitis is Turning Up in People
Hepatitis is a term for liver inflammation. Hepatitis A, B, C, D, and E are caused by viruses.
MAY 23, 2020
Microbiology
MAY 23, 2020
The FDA Yanks Some COVID-19 Antibody Tests From the Market
The massive demand for diagnostic testing led the FDA to open a short window for many testing products to go to market w ...
JUN 01, 2020
Microbiology
JUN 01, 2020
The Most Common Marine Microbe Has a Virus in Its Genome
Single-celled ocean microbes known as Pelagibacter or SAR11 make up about 25 percent of the plankton on the planet.
Loading Comments...