1Z6I

Crystal structure of the ectodomain of Drosophila transmembrane receptor PGRP-LCa

Summary for 1Z6I

• Entry DOI: 10.2210/pdb1z6i/pdb
• Descriptor: Peptidoglycan-recognition protein-LC, 2-acetamido-2-deoxy-beta-D-glucopyranose, SULFATE ION, ... (4 entities in total)
• Functional Keywords: mixed beta-sheet, 3/10 helix, membrane protein, immune system
• Biological source: Drosophila melanogaster (fruit fly)
• Cellular location: Membrane; Single-pass type II membrane protein: Q9GNK5
• Total number of polymer chains: 1
• Total formula weight: 19114.61

Authors

Chang, C.-I.,Ihara, K.,Chelliah, Y.,Mengin-Lecreulx, D.,Wakatsuki, S.,Deisenhofer, J. (deposition date: 2005-03-22, release date: 2005-07-19, Last modification date: 2024-11-13)

Primary citation

Chang, C.-I.,Ihara, K.,Chelliah, Y.,Mengin-Lecreulx, D.,Wakatsuki, S.,Deisenhofer, J.
Structure of the ectodomain of Drosophila peptidoglycan-recognition protein LCa suggests a molecular mechanism for pattern recognition
Proc.Natl.Acad.Sci.Usa, 102:10279-10284, 2005

PubMed Abstract: The peptidoglycan-recognition protein LCa (PGRP-LCa) is a transmembrane receptor required for activation of the Drosophila immune deficiency pathway by monomeric Gram-negative peptidoglycan. We have determined the crystal structure of the ectodomain of PGRP-LCa at 2.5-A resolution and found two unique helical insertions in the LCa ectodomain that disrupt an otherwise L-shaped peptidoglycan-docking groove present in all other known PGRP structures. The deficient binding of PGRP-LCa to monomeric peptidoglycan was confirmed by biochemical pull-down assays. Recognition of monomeric peptidoglycan involves both PGRP-LCa and -LCx. We showed that association of the LCa and LCx ectodomains in vitro depends on monomeric peptidoglycan. The presence of a defective peptidoglycan-docking groove, while preserving a unique role in mediating monomeric peptidoglycan induction of immune response, suggests that PGRP-LCa recognizes the exposed structural features of a monomeric muropeptide when the latter is bound to and presented by the ectodomain of PGRP-LCx. Such features include N-acetyl glucosamine and the anhydro bond in the glycan of the muropeptide, which have been demonstrated to be critical for immune stimulatory activity.

PubMed: 16006509
DOI: 10.1073/pnas.0504547102

Experimental method

X-RAY DIFFRACTION (2.5 Å)