4HL0

Crystal structure of full-length Toxascaris leonina galectin

Summary for 4HL0

• Entry DOI: 10.2210/pdb4hl0/pdb
• Related: 3NV1
• Descriptor: galectin (2 entities in total)
• Functional Keywords: carbohydrate recognition domain, galectin, a regulatory molecule, the host immune system, sugar binding protein
• Biological source: Toxascaris leonina
• Total number of polymer chains: 2
• Total formula weight: 62990.58

Authors

Jeong, M.S. (deposition date: 2012-10-15, release date: 2013-02-06, Last modification date: 2024-03-20)

Primary citation

Jeong, M.S.,Hwang, H.G.,Yu, H.S.,Jang, S.B.
Structure of full-length Toxascaris leonina galectin with two carbohydrate-recognition domains.
Acta Crystallogr.,Sect.D, 69:168-175, 2013

PubMed Abstract: The full-length crystal structure of Toxascaris leonine galectin (Tl-gal), a galectin-9 homologue protein, was determined at a resolution of 2.0 Å. Galectin-9 exhibits a variety of biological functions, including cell aggregation, eosinophil chemoattraction, activation and apoptosis of murine thymocytes, T cells and human melanoma cells. Similar to this galectin, Tl-gal may function as a regulatory molecule in the host immune system; however, no molecular or structural information has been reported for Tl-gal. Moreover, until now, there have been no reports of a full-length galectin structure. There are two molecules of Tl-gal per asymmetric unit in space group P2(1)2(1)2(1), and the N-terminal and C-terminal carbohydrate-recognition domains (NCRD and CCRD) of Tl-gal are composed of six-stranded β-sheets and five-stranded β-sheets with a short α-helix. The NCRD of Tl-gal resembles that of human galectin-7 and its CCRD resembles human galectin-9, but the residues in the interface and loop regions of the NCRD and CCRD are flexible and are related to interaction. Engagement of the T-cell immunoglobulin mucin-3 (Tim-3) immunoglobulin variable (IgV) domain by a galectin-9 ligand is known to be important for appropriate termination of T-helper 1 immune responses. To investigate the binding site of Tl-gal, the interaction between Tl-gal and Tim-3 was modelled. Tim-3 is docked into a major groove of the Tl-gal structure, which is larger and deeper than the minor groove. The structural information presented here will provide insight into the development of novel anti-inflammatory agents or selective modulators of immune response.

PubMed: 23385453
DOI: 10.1107/S0907444912045106

Experimental method

X-RAY DIFFRACTION (2 Å)