A manuscript with the title “Topological constraints and modular structure in the folding and functional motions of GlpG, an intramembrane protease” has been published in PNAS. This paper uses simulations to investigate the effects of constraining the unfolded ensemble of GlpG in a bilayer on its folding mechanism. Using the detailed folding mechanisms found in this paper, we propose a possible source of the large number of negative phi-values found in our previous experimental work. Otzen lab co-authors include Nicholas P Schafer and Daniel E Otzen. This work is a collaboration with Kresten Lindorff-Larsen at Copenhagen University as well as Ha H Truong and Peter G Wolynes at Rice University.