2RKQ

Crystal structure of drosophila peptidoglycan recognition protein SD (PGRP-SD)

Summary for 2RKQ

• Entry DOI: 10.2210/pdb2rkq/pdb
• Descriptor: Peptidoglycan-recognition protein-SD (2 entities in total)
• Functional Keywords: innate immunity; toll; pattern recognition; pgrp; drosophila, glycoprotein, immune response, secreted, immune system
• Biological source: Drosophila melanogaster (fruit fly)
• Cellular location: Secreted (Probable): Q9VS97
• Total number of polymer chains: 1
• Total formula weight: 18415.69

Authors

Roussel, A.,Royet, J.,Leone, P.,Kellenberger, C. (deposition date: 2007-10-17, release date: 2008-03-25, Last modification date: 2024-11-06)

Primary citation

Leone, P.,Bischoff, V.,Kellenberger, C.,Hetru, C.,Royet, J.,Roussel, A.
Crystal structure of Drosophila PGRP-SD suggests binding to DAP-type but not lysine-type peptidoglycan
Mol.Immunol., 45:2521-2530, 2008

PubMed Abstract: In Drosophila the synthesis of antimicrobial peptides in response to microbial infections is under the control of the Toll and immune deficiency (Imd) signaling pathways. The Toll signaling pathway responds mainly to Gram-positive bacterial and fungal infection while the Imd pathway mediates the response to Gram-negative bacteria. Microbial recognition upstream of Toll involves, at least in part, peptidoglycan recognition proteins (PGRPs). The sensing of Gram-positive bacteria is mediated by the pattern recognition receptors PGRP-SA and Gram-negative binding protein 1 (GNBP1) that cooperate to detect the presence of lysine-type peptidoglycan in the host. Recently it has been shown that a loss-of-function mutation in peptidoglycan recognition protein SD (PGRP-SD) severely exacerbates the PGRP-SA and GNBP1 mutant phenotypes. Here we have solved the crystal structure of PGRP-SD at 1.5A resolution. Comparison with available structures of PGRPs in complex with their peptidoglycan (PGN) ligand strongly suggests a diaminopimelic acid (DAP) specificity for PGRP-SD. This result is supported by pull-down assays with insoluble PGNs. In addition we show that Toll pathway activation after infection by DAP-type PGN containing bacteria is clearly reduced in PGRP-SD mutant flies. Our hypothesis is that the role of PGRP-SD is the recognition of DAP-type PGNs responsible for the activation of the Toll pathway by Gram-negative bacteria.

PubMed: 18304640
DOI: 10.1016/j.molimm.2008.01.015

Experimental method

X-RAY DIFFRACTION (1.5 Å)