1XT5

Crystal Structure of VCBP3, domain 1, from Branchiostoma floridae

Summary for 1XT5

• Entry DOI: 10.2210/pdb1xt5/pdb
• Descriptor: variable region-containing chitin-binding protein 3, SULFATE ION (3 entities in total)
• Functional Keywords: innate immunity, vcbp, primordial antigen receptor, florida lancelet, amphioxus, immune system
• Biological source: Branchiostoma floridae (Florida lancelet)
• Total number of polymer chains: 1
• Total formula weight: 14893.54

Authors

Hernandez Prada, J.A.,Haire, R.N.,Cannon, J.P.,Allaire, M.,Jakoncic, J.,Stojanoff, V.,Litman, G.W.,Ostrov, D.A. (deposition date: 2004-10-21, release date: 2005-10-04, Last modification date: 2024-11-20)

Primary citation

Haire, R.N.,Allaire, M.,Jakoncic, J.,Stojanoff, V.,Cannon, J.P.,Litman, G.W.,Ostrov, D.A.
Ancient evolutionary origin of diversified variable regions demonstrated by crystal structures of an immune-type receptor in amphioxus.
Nat.Immunol., 7:875-882, 2006

PubMed Abstract: Although the origins of genes encoding the rearranging binding receptors remain obscure, it is predicted that their ancestral forms were nonrearranging immunoglobulin-type domains. Variable region-containing chitin-binding proteins (VCBPs) are diversified immune-type molecules found in amphioxus (Branchiostoma floridae), an invertebrate that diverged early in deuterostome phylogeny. To study the potential evolutionary relationships between VCBPs and vertebrate adaptive immune receptors, we solved the structures of both a single V-type domain (to 1.15 A) and a pair of V-type domains (to 1.85 A) from VCBP3. The deduced structures show integral features of the ancestral variable-region fold as well as unique features of variable-region pairing in molecules that may reflect characteristics of ancestral forms of diversified immune receptors found in modern-day vertebrates.

PubMed: 16799561
DOI: 10.1038/ni1359

Experimental method

X-RAY DIFFRACTION (1.15 Å)