3AQG

Crystal structure of human pancreatic secretory protein ZG16b

Summary for 3AQG

• Entry DOI: 10.2210/pdb3aqg/pdb
• Related: 3APA
• Descriptor: Zymogen granule protein 16 homolog B, PHOSPHATE ION (3 entities in total)
• Functional Keywords: beta-prism fold, unknown function
• Biological source: Homo sapiens (human)
• Cellular location: Secreted (Potential): Q96DA0
• Total number of polymer chains: 2
• Total formula weight: 34933.06

Authors

Kanagawa, M.,Satoh, T.,Nakano, Y.,Kojima-Aikawa, K.,Yamaguchi, Y. (deposition date: 2010-11-01, release date: 2010-12-08, Last modification date: 2023-11-01)

Primary citation

Kanagawa, M.,Satoh, T.,Ikeda, A.,Nakano, Y.,Yagi, H.,Kato, K.,Kojima-Aikawa, K.,Yamaguchi, Y.
Crystal structures of human secretory proteins ZG16p and ZG16b reveal a Jacalin-related beta-prism fold
Biochem.Biophys.Res.Commun., 2010

PubMed Abstract: ZG16p is a secretory protein that mediates condensation-sorting of pancreatic enzymes to the zymogen granule membrane in pancreatic acinar cells. ZG16p interacts with glycosaminoglycans and the binding is considered to be important for condensation-sorting of pancreatic enzymes. ZG16b/PAUF, a paralog of ZG16p, has recently been found to play a role in gene regulation and cancer metastasis. However, the detailed functions of ZG16p and ZG16b remain to be clarified. Here, in order to obtain insights into structure-function relationships, we conducted crystallographic studies of human ZG16p lectin as well as its paralog, ZG16b, and determined their crystal structures at 1.65 and 2.75 Å resolution, respectively. ZG16p has a Jacalin-related β-prism fold, the first to be reported among mammalian lectins. The putative sugar-binding site of ZG16p is occupied by a glycerol molecule, mimicking the mannose bound to Jacalin-related mannose-binding-type plant lectins such as Banlec. ZG16b also has a β-prism fold, but some amino acid residues of the putative sugar-binding site differ from those of the mannose-type binding site suggesting altered preference. A positively charged patch, which may bind sulfated groups of the glycosaminoglycans, is located around the putative sugar-binding site of ZG16p and ZG16b. Taken together, we suggest that the sugar-binding site and the adjacent basic patch of ZG16p and ZG16b cooperatively form a functional glycosaminoglycan-binding site.

PubMed: 21110947
DOI: 10.1016/j.bbrc.2010.11.093

Experimental method

X-RAY DIFFRACTION (2.75 Å)