4PBO

Crystal structure of zebrafish short-chain pentraxin protein without calcium ions

Summary for 4PBO

• Entry DOI: 10.2210/pdb4pbo/pdb
• Related: 4PBP
• Descriptor: C-reactive protein (2 entities in total)
• Functional Keywords: acute phase protein, pentraxin, immune system
• Biological source: Danio rerio (Zebrafish)
• Total number of polymer chains: 1
• Total formula weight: 23560.49

Authors

Chen, R.,Qi, J.X.,George, F.G.,Xia, C. (deposition date: 2014-04-13, release date: 2015-03-25, Last modification date: 2024-10-09)

Primary citation

Chen, R.,Qi, J.,Yuan, H.,Wu, Y.,Hu, W.,Xia, C.
Crystal structures for short-chain pentraxin from zebrafish demonstrate a cyclic trimer with new recognition and effector faces.
J.Struct.Biol., 189:259-268, 2015

PubMed Abstract: Short-chain pentraxins (PTXs), including CRP and SAP, are innate pattern recognition receptors that play vital roles in the recognition and elimination of various pathogenic bacteria by triggering the classical complement pathway through C1q. Similar to antibodies, pentraxins can also activate opsonisation and phagocytosis by interacting with Fc receptors (FcRs). Various structural studies on human PTXs have been performed, but there are no reports about the crystal structure of bony fish pentraxins. Here, the crystal structures of zebrafish PTX (Dare-PTX-Ca and Dare-PTX) are presented. Both Dare-PTX-Ca and Dare-PTX are cyclic trimers, which are new forms of crystallised pentraxins. The structures reveal that the ligand-binding pocket (LBP) in the recognition face of Dare-PTX is deep and narrow. Homology modelling shows that LBPs from different Dare-PTX loci differ in shape, reflecting their specific recognition abilities. Furthermore, in comparison with the structure of hCPR, a new C1q binding mode was identified in Dare-PTX. In addition, the FcR-binding sites of hSAP are partially conserved in Dare-PTX. These results will shed light on the understanding of a primitive PTX in bony fish, which evolved approximately 450 million years ago.

PubMed: 25592778
DOI: 10.1016/j.jsb.2015.01.001

Experimental method

X-RAY DIFFRACTION (1.701 Å)