Figure 6.
Figure 6. A proposed general mechanism for intramembrane
proteases. In this model, presenilin, S2P and signal-peptide
peptidase may each contain a water cavity that opens to the
cytoplasm or extracellular region. As in rhomboid GlpG, this
water-accessible cavity is probably protected from the
hydrophobic lipid bilayer by -helices
and embedded loops. Before catalysis, one or more of the
surrounding helices undergoes a structural switch that opens a
lateral gate to allow entry of substrate protein. Star denotes
active site.
The above figure is reprinted
by permission from Macmillan Publishers Ltd:
Nat Struct Mol Biol
(2006,
13,
1084-1091)
copyright 2006.
-helices
and embedded loops. Before catalysis, one or more of the
surrounding helices undergoes a structural switch that opens a
lateral gate to allow entry of substrate protein. Star denotes
active site.