--Must See--

Bioinformatics Summer Internship 2024 With Hands-On-Training + Project / Dissertation - 30 Days, 3 Months & 6 Months Duration

"text-align: center;">Bacterial Adhesion Protein Could Help Find New Antibiotics

Many pathogenic bacteria, including Streptococcus gordonii, possess a pathway for the cellular export of a single serine-rich-repeat protein that mediates the adhesion of bacteria to host cells and the extracellular matrix.

Now, researchers at Harvard Medical School, the University of California–San Francisco, and the University of Georgia have described how the protein that allows strep and staph bacteria to stick to human cells is prepared and packaged.

An important class of extracellular molecules produced by pathogenic bacteria are adhesins, proteins that enable bacteria to adhere to host cells. For unknown reasons, the SRR (serine-rich-repeat) adhesins of Staphylococcus and Streptococcus bacteria- pathogens that can be involved in serious infections such as bacterial meningitis, bacterial pneumonia and pericarditis- are transported through a secretion pathway that is similar to the standard system, but dedicated solely to adhesin.

Tom Rapoport, a professor at Harvard Medical School who oversaw the new study, wanted to understand what exactly these dedicated molecular supply chains were doing. “I was intrigued by the fact that there is a second secretion system in some bacteria that is separate from the canonical secretion system and is just dedicated to the secretion of one protein,” he said. “There is a whole machinery, and it’s only doing one thing.

The researchers found that in order to be transported, the adhesin protein needed to be modified with specific sugars by three enzymes acting in a specific sequence. These sugar modifications stabilize the protein and enhance its stickiness to target cells.

The experiments the team carried out indicated that two proteins in the adhesin-specific pathway, whose function had previously been mysterious, seemed to be able to bind to these sugars, presumably enabling them to carry the adhesin to the cell membrane where adhesin’s dedicated exit channel is located.

It’s a complicated system because it involves protein modification, chaperone activity and membrane targeting, so we encountered a lot of challenges,” said Yu Chen who led the investigation.

The reason that these bacteria use this separate export pathway for adhesins remains elusive. But because this pathway is unique to strep and staph bacteria, the new understanding of its components could help researchers develop highly targeted antibiotics to treat infections caused by these bacteria in the future.

In search of the perfect burger. Serial eater. In her spare time, practises her "Vader Voice". Passionate about dance. Real Weird.