6M5M

SPL-1 - GlcNAc complex

Summary for 6M5M

• Entry DOI: 10.2210/pdb6m5m/pdb
• Related: 6A7T
• Descriptor: N-acetylglucosamine-specific lectin, CALCIUM ION, 2-acetamido-2-deoxy-beta-D-glucopyranose, ... (5 entities in total)
• Functional Keywords: lectin, glcnac, spl-1, sugar binding protein
• Biological source: Saxidomus purpuratus; More
• Total number of polymer chains: 2
• Total formula weight: 36483.07

Authors

Unno, H.,Hatakeyama, T. (deposition date: 2020-03-11, release date: 2020-06-10, Last modification date: 2024-10-30)

Primary citation

Unno, H.,Higuchi, S.,Goda, S.,Hatakeyama, T.
Novel carbohydrate-recognition mode of the invertebrate C-type lectin SPL-1 from Saxidomus purpuratus revealed by the GlcNAc-complex crystal in the presence of Ca2.
Acta Crystallogr.,Sect.F, 76:271-277, 2020

PubMed Abstract: The C-type lectins SPL-1 and SPL-2 from the bivalve Saxidomus purpuratus are composed of A and B chains and of two B chains, respectively. They bind specific carbohydrates containing acetamido groups, such as N-acetylglucosamine (GlcNAc) and N-acetylgalactosamine (GalNAc), in a Ca-independent manner. Unlike ordinary C-type lectins, which require Ca ions for carbohydrate recognition, these lectins recognize specific carbohydrates mainly through interactions with the acetamido group without Ca ions, even though Ca enhances the binding affinity of these lectins, especially SPL-1. In the present study, the crystal structure of the SPL-1-GlcNAc complex in the presence of Ca revealed that the binding of SPL-1 to GlcNAc is stabilized by hydrogen bonds to the water molecule(s) coordinating Ca, whereas in ordinary C-type lectins Ca directly forms coordinate bonds to the hydroxy groups of carbohydrates. These differences may also allow SPL-1 and SPL-2 to recognize both GlcNAc and GalNAc, which have different orientations of the 4-hydroxy group.

PubMed: 32510468
DOI: 10.1107/S2053230X20007256

Experimental method

X-RAY DIFFRACTION (1.7 Å)