Chaperones Play Hot Potato with Unfolded Proteins in the Periplasm

Seminar Details

Host: Dr. Josh Wand

Time: 4:00pm-5:00pm

Location: BICH Rm 108

Seminar Abstract

The periplasm is a ~170-200 Å wide cellular compartment surrounding a Gram–negative bacteria and bordered by two membranes, termed the “inner” (or cytoplasmic) and “outer” membrane. Both soluble and outer membrane proteins are secreted into the periplasm using the chemical potential of the energized inner membrane or cytoplasmic sources of ATP. However, the periplasm itself is devoid of an external energy source and is permeable to many small molecules, Moreover, bacterial outer membranes are not energized like their cytoplasmic counterparts. These cellular challenges and conditions raise many questions related to the mechanisms of how nascent unfolded protein chains are sorted to outer membranes and how periplasmic chaperones function to ensure efficient biogenesis of their outer membrane proteins clients. We are using a combination of experiments and computation to interrogate mechanistic models for this periplasmic process and find that a simultaneous consideration of all competing reactions leads to insight into the controls at work in this cellular compartment