5OXS

Crystal structure of human lung surfactant protein D trimeric fragment with bound ligand Salmonella enterica Minnesota R5 oligosaccharide

Summary for 5OXS

• Entry DOI: 10.2210/pdb5oxs/pdb
• Related: 5OXR
• Descriptor: Pulmonary surfactant-associated protein D, alpha-D-glucopyranose-(1-3)-L-glycero-alpha-D-manno-heptopyranose-(1-3)-L-glycero-alpha-D-manno-heptopyranose-(1-5)-4,7-anhydro-3-deoxy-D-gluco-oct-2-ulosonic acid, CALCIUM ION, ... (4 entities in total)
• Functional Keywords: trimeric recombinant collectin fragment, neck+crd, alpha-helical coiled coil, carbohydrate recognition domain, lectin, sugar binding protein, surfactant protein
• Biological source: Homo sapiens (Human)
• Total number of polymer chains: 3
• Total formula weight: 59005.21

Authors

Shrive, A.K.,Greenhough, T.J. (deposition date: 2017-09-07, release date: 2018-06-20, Last modification date: 2024-10-16)

Primary citation

Littlejohn, J.R.,da Silva, R.F.,Neale, W.A.,Smallcombe, C.C.,Clark, H.W.,Mackay, R.A.,Watson, A.S.,Madsen, J.,Hood, D.W.,Burns, I.,Greenhough, T.J.,Shrive, A.K.
Structural definition of hSP-D recognition of Salmonella enterica LPS inner core oligosaccharides reveals alternative binding modes for the same LPS.
PLoS ONE, 13:e0199175-e0199175, 2018

PubMed Abstract: The crystal structures of a biologically and therapeutically active recombinant homotrimeric fragment of native human SP-D (hSP-D) complexed with the inner core oligosaccharide of the Salmonella enterica sv Minnesota rough strains R5 and R7 (rough mutant chemotypes Rc and Rd1) have been determined. The structures reveal that hSP-D specifically and preferentially targets the LPS inner core via the innermost conserved Hep-Kdo pair with the flexibility for alternative recognition when this preferred epitope is not available for binding. Hep-Kdo binding is achieved through calcium dependent recognition of the heptose dihydroxyethyl side chain coupled with specific interactions between the Kdo and the binding site flanking residues Arg343 and Asp325 with evidence for an extended binding site for LPS inner cores containing multiple Kdo residues. In one subunit of the R5-bound structure this preferred mode of binding is precluded by the crystal lattice and oligosaccharide is bound through the terminal inner core glucose. The structures presented here thus provide unique multiple insights into the recognition and binding of bacterial LPS by hSP-D. Not only is it demonstrated that hSP-D targets the highly conserved LPS proximal inner core Hep-Kdo motif, but also that hSP-D can recognise either terminal or non-terminal sugars and has the flexibility and versatility to adopt alternative strategies for bacterial recognition, utilising alternative LPS epitopes when the preferred inner core Hep-Kdo disaccharide is not available for binding.

PubMed: 29912941
DOI: 10.1371/journal.pone.0199175

Experimental method

X-RAY DIFFRACTION (1.65 Å)