9.B.104.1.7
Rhomboid protease (peptidase) of 192 aas and 6 TMSs, GlpG. The structure has been solved at 2.2 Å resolution, revealing the relative disposition of the nucleophilic serine to the general base/acid function of the conserved histidine (Lemieux et al. 2007). The active site is inside the membrane, but near the surface, to release the hydrophilic ectodomain of its single TMS substrate. These enzymes may thin the membrane, allowing access of water to the active site. There is a cavity adjacent to the cleavage site containing ordered water molecules, involved in access to the substrate before cleavage (Sanders and Hutchison 2018). Factors that control the force needed to unfold a membrane protein in silico depend on the mode of denaturation (Faruk et al. 2023).