1SXR image
Deposition Date 2004-03-31
Release Date 2004-06-29
Last Version Date 2024-10-16
Entry Detail
PDB ID:
1SXR
Keywords:
Title:
Drosophila Peptidoglycan Recognition Protein (PGRP)-SA
Biological Source:
Source Organism:
Method Details:
Experimental Method:
Resolution:
1.56 Å
R-Value Free:
0.21
R-Value Work:
0.17
R-Value Observed:
0.18
Space Group:
C 1 2 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Peptidoglycan recognition protein SA CG11709-PA
Gene (Uniprot):PGRP-SA
Chain IDs:A, B
Chain Length:183
Number of Molecules:2
Biological Source:Drosophila melanogaster
Primary Citation
Crystal structure of the Drosophila peptidoglycan recognition protein (PGRP)-SA at 1.56 A resolution
J.Mol.Biol. 340 909 917 (2004)
PMID: 15223330 DOI: 10.1016/j.jmb.2004.04.077

Abstact

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.

Legend

Protein

Chemical

Disease

Primary Citation of related structures