2DSU

Binding of chitin-like polysaccharide to protective signalling factor: Crystal structure of the complex formed between signalling protein from sheep (SPS-40) with a tetrasaccharide at 2.2 A resolution

Replaces:  2AO8

Summary for 2DSU

• Entry DOI: 10.2210/pdb2dsu/pdb
• Related: 2DPE 2ESC 2dsv 2dsw
• Descriptor: Chitinase-3-like protein 1, alpha-D-mannopyranose-(1-4)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-alpha-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-alpha-D-glucopyranose, ... (4 entities in total)
• Functional Keywords: sps-40, oligosaccharides, glycoprotein, signaling protein
• Biological source: Ovis aries (sheep)
• Total number of polymer chains: 1
• Total formula weight: 42192.28

Authors

Srivastava, D.B.,Ethayathulla, A.S.,Kumar, J.,Singh, N.,Sharma, S.,Kaur, P.,Bhushan, A.,Singh, T.P. (deposition date: 2006-07-07, release date: 2006-07-25, Last modification date: 2024-10-30)

Primary citation

Srivastava, D.B.,Ethayathulla, A.S.,Kumar, J.,Somvanshi, R.K.,Sharma, S.,Dey, S.,Singh, T.P.
Carbohydrate binding properties and carbohydrate induced conformational switch in sheep secretory glycoprotein (SPS-40): crystal structures of four complexes of SPS-40 with chitin-like oligosaccharides
J.Struct.Biol., 158:255-266, 2007

PubMed Abstract: Crystal structures of four complexes of sheep secretory glycoprotein (SPS-40) with N-acetylglucosamine oligosaccharides (GlcNAc(n), (n=3-6)) have been determined at moderate resolutions. The binding studies of SPS-40 have been carried out using fluorescence spectroscopy and Surface Plasmon Resonance (SPR). Structure determinations of four complexes have shown a novel binding pattern of GlcNAc(n) molecules to SPS-40. The results indicate that the most preferred recognition region in the carbohydrate binding groove in SPS-40 is at subsites -4 to -2 among which subsite -2 provides the maximum interactions with carbohydrate residues. These structures have also shown that the interactions of GlcNAc3 and GlcNAc4 do not perturb the protein structure and those of GlcNAc5 induce partial conformational changes while in the case of GlcNAc6 the partially closed binding groove opened up completely. As in other SPX-40 structures, SPS-40 structure contains three overlapping flexible surface segments, His188-His197, Phe202-Arg212 and Phe244-Pro260 with several charged residues protruding outwardly. It creates a cluster of positive charges with a flexible base thus indicating a good scope of promoting the intermolecular interactions. This protein is glycosylated at Asn39 and may recognize other receptors having sugar binding sites. It appears that SPS-40 may involve both carbohydrate and protein bindings. The systematic carbohydrate-binding studies and the detailed structural results of four protein-carbohydrate complexes provide an excellent insight into the mechanism of carbohydrate binding. These are the first studies of this kind on secretory glycoproteins and their interactions with carbohydrates.

PubMed: 17188513
DOI: 10.1016/j.jsb.2006.11.002

Experimental method

X-RAY DIFFRACTION (2.2 Å)