From Proteopediaproteopedia link
Crystal structure of GlpG
Publication Abstract from PubMed
Escherichia coli GlpG is an integral membrane protein that belongs to the widespread rhomboid protease family. Rhomboid proteases, like site-2 protease (S2P) and gamma-secretase, are unique in that they cleave the transmembrane domain of other membrane proteins. Here we describe the 2.1 A resolution crystal structure of the GlpG core domain. This structure contains six transmembrane segments. Residues previously shown to be involved in catalysis, including a Ser-His dyad, and several water molecules are found at the protein interior at a depth below the membrane surface. This putative active site is accessible by substrate through a large 'V-shaped' opening that faces laterally towards the lipid, but is blocked by a half-submerged loop structure. These observations indicate that, in intramembrane proteolysis, the scission of peptide bonds takes place within the hydrophobic environment of the membrane bilayer. The crystal structure also suggests a gating mechanism for GlpG that controls substrate access to its hydrophilic active site.
Crystal structure of a rhomboid family intramembrane protease.,Wang Y, Zhang Y, Ha Y Nature. 2006 Nov 9;444(7116):179-80. Epub 2006 Oct 11. PMID:17051161
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.