The outer membrane of bacteria contains many proteins that form tiny pores. They are important for absorbing nutrients and transmitting signals into the cell. The research group of Sebastian Hiller, Professor of Structural Biology at the Biozentrum, University of Basel, has now shown for the first time at atomic resolution, that these pore proteins are transported in an unstructured, constantly changing state to the outer bacterial membrane. This landmark study was recently published in the scientific journal "Nature Structural and Molecular Biology".
The cell membrane of a bacterium is a natural barrier to the environment and at the same time, their door to the world. Gram-negative bacteria surround themselves with two membrane layers. They communicate with the environment through proteins that form tiny pores in the outer cell membrane. How these membrane proteins reach their target destination in the bacterium Escherichia coli could now be observed for the first time at the atomic level by Professor Sebastian Hiller, from the Biozentrum at the University of Basel.
Molecular "ferry" ensures safe protein transport
New proteins are produced in the protein factories inside the cell. Proteins destined for the outer membrane require a molecular "ferry" to remain intact as they pass the aqueous layer between the two membranes. The protein Skp is such a ferry, transporting the not yet folded proteins across the periplasmic space. At the outer membrane, they fold into their three-dimensional structure and incorporate into the outer membrane.
The current study by Hiller provides an exceptional and deep insight into this transport mechanism. The membrane protein is loosely embedded in the solid structure of Skp during transport and does not adopt on a defined spatial structure itself. "Amazingly, the unfolded protein changes its state constantly faster than thousand times per second and more than ten million times during th
|Contact: Olivia Poisson|
University of Basel