Basbous, N., Coste, F., Leone, P., Vincentelli, R., Royet, J., Kellenberger, C., Roussel, A. (2011). The Drosophila peptidoglycan-recognition protein LF interacts with peptidoglycan-recognition protein LC to downregulate the Imd pathway.  EMBO Rep. 12(4): 327--333.

FBrf0213381

Research paper

The peptidoglycan (PGN)-recognition protein LF (PGRP-LF) is a specific negative regulator of the immune deficiency (Imd) pathway in Drosophila. We determine the crystal structure of the two PGRP domains constituting the ectodomain of PGRP-LF at 1.72 and 1.94 Å resolution. The structures show that the LFz and LFw domains do not have a PGN-docking groove that is found in other PGRP domains, and they cannot directly interact with PGN, as confirmed by biochemical-binding assays. By using surface plasmon resonance analysis, we show that the PGRP-LF ectodomain interacts with the PGRP-LCx ectodomain in the absence and presence of tracheal cytotoxin. Our results suggest a mechanism for downregulation of the Imd pathway on the basis of the competition between PRGP-LCa and PGRP-LF to bind to PGRP-LCx.

PMC3077246 (PMC) (EuropePMC)