1sxr
From Proteopedia
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Drosophila Peptidoglycan Recognition Protein (PGRP)-SA
Overview
Peptidoglycan recognition proteins (PGRPs) form a recently discovered, protein family, which is conserved from insect to mammals and is, implicated in the innate immune system by interacting with/or degrading, microbial peptidoglycans (PGNs). Drosophila PGRP-SA is a member of this, family of pattern recognition receptors and is involved in insect Toll, activation. We report here the crystal structure of PGRP-SA at 1.56 A, resolution, which represents the first example of a "recognition" PGRP., Comparison with the catalytic Drosophila PGRP-LB reveals an overall, structure conservation with an L-shaped hydrophilic groove that is likely, the PGN carbohydrate core binding site, but further suggests some possible, functional homology between recognition and catalytic PGRPs. Consistent, with sequence analysis, PGRP-SA does not contain the canonical, zinc-binding residues found in catalytic PGRPs. However, substitution of, the zinc-binding cysteine residue by serine, along with an altered, coordinating histidine residue, assembles a constellation of residues that, resembles a modified catalytic triad. The serine/histidine juxtaposition, to a threonine residue and a carbonyl oxygen atom, along with conservation, of the catalytic water molecule found in PGRP-LB, tantalizingly suggests, some hydrolytic function for this member of receptor PGRPs.
About this Structure
1SXR is a Single protein structure of sequence from Drosophila melanogaster with SO4 and EDO as ligands. Full crystallographic information is available from OCA.
Reference
Crystal structure of the Drosophila peptidoglycan recognition protein (PGRP)-SA at 1.56 A resolution., Reiser JB, Teyton L, Wilson IA, J Mol Biol. 2004 Jul 16;340(4):909-17. PMID:15223330
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