IISER team’s find may help fight drug-resistant infections
A team of scientists at the Indian Institute of Science Education and Research (IISER) in Pune claims to have determined the atomic structure of McrBC — a complex bacterial protein which helps prevent viral infections in a bacterial cell and functions as a molecular scissor.

The pathbreaking structure of the McrBC as determined by Dr. Kayarat Saikrishnan, an associate professor of biology and his team at the IISER, was published last month in two prestigious, peer-reviewed scientific journals — Nature Communications and Nucleic Acids Research (which is published by the Oxford university Press) — and is said to be a major step towards understanding the working of the molecular scissors.

This is the first report of the high-resolution structure from India determined using electron cryomicroscopy, commonly known as cryo-EM.

Speaking to The Hindu about the importance of the McrBC’s structure, Dr. Saikrishnan said the understanding of the molecular scissors would aid in combating multidrug resistant microbes. “As McrBC-like molecular scissors prevent viral infections of the bacterial cell, the design of such ‘inhibitors’ will be facilitated by their 3D structures,” he said.

“[The McrBC’s] unique feature is that it requires to be powered by an inbuilt motor that uses GTP (guanosine triphosphate) — an energy currency of the bacterial cell — as ‘fuel’ to cut the foreign DNA. It is important to know how the machinery works in order to be able to regulate it. If you have a drug-resistant strain in bacteria, it is often seen that this machinery is absent and they become resistant to antibiotics,” he said, remarking that the technological revolution in the field of cryo-EM had allowed the determination of the three-dimensional position of every atom in biomolecules such as the McrBC.

Source: https://www.thehindu.com/sci-tech/health/iiser-teams-find-may-help-fight-drug-resistant-infections/article29255577.ece