2APH

Crystal structure of human PGRP-IalphaC in complex with muramyl pentapeptide

Summary for 2APH

• Entry DOI: 10.2210/pdb2aph/pdb
• Related: 1SK3 1SK4 1TWQ
• Descriptor: Peptidoglycan recognition protein I-alpha, muramyl pentapeptide, SULFATE ION, ... (5 entities in total)
• Functional Keywords: pgrps, lys-type, peptidoglycan, complex, immune system
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 4
• Total formula weight: 38295.39

Authors

Guan, R.,Roychowdjury, A.,Boons, G.,Mariuzza, R.A. (deposition date: 2005-08-16, release date: 2006-06-27, Last modification date: 2024-02-28)

Primary citation

Guan, R.,Brown, P.H.,Swaminathan, C.P.,Roychowdhury, A.,Boons, G.J.,Mariuzza, R.A.
Crystal structure of human peptidoglycan recognition protein I alpha bound to a muramyl pentapeptide from Gram-positive bacteria.
Protein Sci., 15:1199-1206, 2006

PubMed Abstract: Peptidoglycan recognition proteins (PGRPs) are pattern recognition receptors of the innate immune system that bind bacterial peptidoglycans (PGNs). We determined the crystal structure, to 2.1 A resolution, of the C-terminal PGN-binding domain of human PGRP-I alpha in complex with a muramyl pentapeptide (MPP) from Gram-positive bacteria containing a complete peptide stem (L-Ala-D-isoGln-L-Lys-D-Ala-D-Ala). The structure reveals important features not observed previously in the complex between PGRP-I alpha and a muramyl tripeptide lacking D-Ala at stem positions 4 and 5. Most notable are ligand-induced structural rearrangements in the PGN-binding site that are essential for entry of the C-terminal portion of the peptide stem and for locking MPP in the binding groove. We propose that similar structural rearrangements to accommodate the PGN stem likely characterize many PGRPs, both mammalian and insect.

PubMed: 16641493
DOI: 10.1110/ps.062077606

Experimental method

X-RAY DIFFRACTION (2.1 Å)