SLAC researcher discovers giant cavity in key tuberculosis molecule
The protein contains a “huge” interior pocket, the likes of which has never before been seen, that appears capable of passing a wide range of other molecules into the bacterial cell.
Cornelius Gati, a structural biologist at SLAC, discovered the pocket while investigating the role this “transporter protein” on the surface of tuberculosis bacteria plays in sucking up vitamin B12 from surrounding cells.
As far as anyone knew, transporter proteins that import molecules into cells tend to be quite specialized, with nooks and crannies tailored to grab onto particular molecules and move them into cells.
This one, Gati found, was a generalist that could in principle bring in small nutrients, larger molecules like vitamin B12 or even some antibiotics.
In theory, the new findings could lead to new ways to treat tuberculosis, but for the moment Gati and colleagues are simply trying to get a better handle on what the protein can and cannot transport – as well as what purpose such an odd protein might serve.
“We’ve never seen anything like this before,” Gati said.
“It doesn’t really make sense.” ■