3ODJ

Crystal structure of H. influenzae rhomboid GlpG with disordered loop 4, helix 5 and loop 5

Summary for 3ODJ

• Entry DOI: 10.2210/pdb3odj/pdb
• Related: 2IC8 2IRV 2NR9 2NRF 2O7L 3B44 3B45
• Descriptor: Rhomboid protease glpG (2 entities in total)
• Functional Keywords: rhomboid peptidase, membrane protein, hydrolase
• Biological source: Haemophilus influenzae
• Cellular location: Cell inner membrane ; Multi-pass membrane protein : P44783
• Total number of polymer chains: 1
• Total formula weight: 22140.92

Authors

Brooks, C.L.,Lazareno-Saez, C.,Lamoureux, J.S.,Mak, M.W.,Lemieux, M.J. (deposition date: 2010-08-11, release date: 2011-02-23, Last modification date: 2024-02-21)

Primary citation

Brooks, C.L.,Lazareno-Saez, C.,Lamoureux, J.S.,Mak, M.W.,Lemieux, M.J.
Insights into Substrate Gating in H. influenzae Rhomboid.
J.Mol.Biol., 407:687-697, 2011

PubMed Abstract: Rhomboids are a remarkable class of serine proteases that are embedded in lipid membranes. These membrane-bound enzymes play key roles in cellular signaling events, and disruptions in these events can result in numerous disease pathologies, including hereditary blindness, type 2 diabetes, Parkinson's disease, and epithelial cancers. Recent crystal structures of rhomboids from Escherichia coli have focused on how membrane-bound substrates gain access to a buried active site. In E. coli, it has been shown that movements of loop 5, with smaller movements in helix 5 and loop 4, act as substrate gate, facilitating inhibitor access to rhomboid catalytic residues. Herein we present a new structure of the Haemophilus influenzae rhomboid hiGlpG, which reveals disorder in loop 5, helix 5, and loop 4, indicating that, together, they represent mobile elements of the substrate gate. Substrate cleavage assays by hiGlpG with amino acid substitutions in these mobile regions demonstrate that the flexibilities of both loop 5 and helix 5 are important for access of the substrates to the catalytic residues. Mutagenesis indicates that less mobility by loop 4 is required for substrate cleavage. A reexamination of the reaction mechanism of rhomboid substrates, whereby cleavage of the scissile bond occurs on the si-face of the peptide bond, is discussed.

PubMed: 21295583
DOI: 10.1016/j.jmb.2011.01.046

Experimental method

X-RAY DIFFRACTION (2.84 Å)