A common example of antibiotic resistance is Methicillin-resistant Staphylococcus aureus (MRSA), the strain of bacteria responsible for thousands of difficult-to-treat infections reported in humans each year.
There is a dispute that remains unresolved as to whether or not this pathway were investigating is involved in MRSA. Its very unclear. By understanding the mechanism, we might be able to find out if this is involved in MRSA or not, Ibba said.
Ibba and Herv Roy, a postdoctoral researcher at Ohio State and lead author of the study, concentrated on exploring the activities of these specific MprF proteins, which are just two of dozens of forms of a class of genes associated with the development of resistance in about 200 bacteria species. They investigated the activity of two forms of MprF from the pathogen Clostridium perfringens, one of the most common sources of food poisoning in the United States.
MprF proteins affect the membranes charge by using an adapter molecule, called transfer RNA (tRNA), to transfer amino acids to the lipids that make up the cell membrane. This action leads to modification of the membrane and the change in its charge.
Ibba and Roy found that both MprF1 and MprF2 perform this same function, but they use different amino acids that lead to the modification. The amino acid lysine has already been identified as a player in this modification, and is used by MprF2. Ibba and Roy found that MprF1, however, uses the amino acid alanine instead. This amino acid also contributes to cell membrane modification and seems to have additional functions that remain unknown.
This is a new function that we discovered, that MprF1 uses alanine, which then allows the cell to fine tune the properties of the membrane, Roy said. Earlier studies found these effects on the membrane, but no one knew what protein caused it.
What makes these protein
|Contact: Michael Ibba|
Ohio State University