Bacteria save energy by producing proteins that moonlight, having different roles at different times, which may also protect the microbes from being killed. The moonlighting activity of one enzyme from the tuberculosis bacterium makes it partially resistant to a family of broad-spectrum antibiotics, according to a paper published in the September issue of the journal Microbiology.
"Glutamate racemase, or MurI, is an enzyme that bacteria use to make the building blocks of cell walls," said Professor Valakunja Nagaraja from the Indian Institute of Science in Bangalore, India. "MurI from Mycobacterium tuberculosis also stops the enzyme DNA gyrase from working, which in turn stops DNA replication and cell division."
The researchers found that the two different functions work independently of one another - the enzyme's ability to make cell wall components does not affect its ability to inhibit DNA gyrase and vice versa.