An unusual bacterium that penetrates and lives inside human cells may offer a new drug target

This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Research underway in the lab of Rebecca Alexander, a professor in Wake Forest University's Department of Chemistry, is shedding light on an unusual human bacterium, Mycoplasma penetrans. Alexander's work to understand how and why this unique pathogen acts as it does could one day lead to new classes of drugs that better target illnesses associated with this particular pathogen, as well as others that act similarly.

The research "just expands the possibilities of antibacterial therapies," said Alexander, also a senior associate dean for research and community engagement. "M. penetrans is weird because it actually penetrates into the host cell itself. It's an intracellular parasitic pathogen.

These bacteria have a sort of spear on the end that they insert into the human host, and then they live inside the host cell. That makes it more like a virus because that's how viruses work. Most bacteria don't do that, but this bacterium does." Her research delves into the intricacies of cell biology—how cells, and specifically M. penetrans, carry out key functions.

This unusual pathogen, first discovered as a co-infection in immunocompromised patients with HIV, possesses a very small genome, or the collection of DNA it needs to survive. M. penetrans relies on the human host for many genes it doesn't contain itself. In the cell, messenger ribonucleic acid (mRNA) carries genetic instructions from DNA inside the nucleus to other parts of the cell.

Another molecule, transfer RNA (tRNA), reads the instructions on the mRNA molecule and brings specific amino acids together to form peptide bonds. Those bonds build full proteins for cellular structure and function. Peptides do things like regulate blood sugar and reduce inflammation.

There are about 20 standard amino acids and corresponding families of tRNAs. Specific enzymes are required to accurately and rapidly attach the correct amino acid to its tRNA partner. The particular enzyme Alexander has studied for several years is methionyl-tRNA synthetase, or MetRS.