6LJR image
Entry Detail
PDB ID:
6LJR
Title:
human galectin-16 R55N/H57R
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2019-12-17
Release Date:
2020-10-14
Method Details:
Experimental Method:
Resolution:
2.00 Å
R-Value Free:
0.21
R-Value Work:
0.16
R-Value Observed:
0.16
Space Group:
C 1 2 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Galectin-16
Chain IDs:A
Chain Length:145
Number of Molecules:1
Biological Source:Homo sapiens
Peptide-like Molecules
PRD_900004
Primary Citation
Human galectin-16 has a pseudo ligand binding site and plays a role in regulating c-Rel-mediated lymphocyte activity.
Biochim Biophys Acta Gen Subj 1865 129755 129755 (2020)
PMID: 33011338 DOI: 10.1016/j.bbagen.2020.129755

Abstact

BACKGROUND The structure of human galectin-16 (Gal-16) has yet to be solved, and its function has remained elusive. METHODS X-ray crystallography was used to determine the atomic structures of Gal-16 and two of its mutants. The Gal-16 oligomer state was investigated by gel filtration, its hemagglutination activity was determined along with its ability to bind lactose using ITC. The cellular distribution of EGFP-tagged Gal-16 in various cell lines was also investigated, and the interaction between Gal-16 and c-Rel was assessed by pull-down studies, microscale thermophoresis and immunofluorescence. RESULTS Unlike other galectins, Gal-16 lacks the ability to bind the β-galactoside lactose. Lactose binding could be regained by replacing an arginine (Arg55) with asparagine, as shown in the crystal structures of two lactose-loaded Gal-16 mutants (R55N and R55N/H57R). Gal-16 was also shown to be monomeric by gel filtration, as well as in crystal structures. Thus, this galectin could not induce erythrocyte agglutination. EGFP-tagged Gal-16 was found to be localized mostly in the nucleus of various cell types, and can interact with c-Rel, a member of NF-κB family. CONCLUSIONS Gal-16 exists as a monomer and its ligand binding is significantly different from that of other prototype galectins, suggesting that it has a novel function(s). The interaction between Gal-16 and c-Rel indicates that Gal-16 may regulate signal transduction pathways via the c-Rel hub in B or T cells at the maternal-fetal interface. GENERAL SIGNIFICANCE The present study lays the foundation for further studies into the cellular and physiological functions of Gal-16.

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