4QQ2

Crystal structure of C1QL1

Summary for 4QQ2

• Entry DOI: 10.2210/pdb4qq2/pdb
• Related: 4qpy 4qqh 4qql 4qqo 4qqp
• Descriptor: C1q-related factor, CADMIUM ION (3 entities in total)
• Functional Keywords: jelly roll fold, c1q, brain-specific angiogenesis inhibitor g-protein coupled receptor, extracellular, protein binding
• Biological source: Mus musculus (mouse)
• Cellular location: Secreted: O88992
• Total number of polymer chains: 3
• Total formula weight: 46859.67

Authors

Ressl, S.,Brunger, A.T. (deposition date: 2014-06-26, release date: 2015-04-15, Last modification date: 2024-02-28)

Primary citation

Ressl, S.,Vu, B.K.,Vivona, S.,Martinelli, D.C.,Sudhof, T.C.,Brunger, A.T.
Structures of C1q-like Proteins Reveal Unique Features among the C1q/TNF Superfamily.
Structure, 23:688-699, 2015

PubMed Abstract: C1q-like (C1QL) -1, -2, and -3 proteins are encoded by homologous genes that are highly expressed in brain. C1QLs bind to brain-specific angiogenesis inhibitor 3 (BAI3), an adhesion-type G-protein coupled receptor that may regulate dendritic morphology by organizing actin filaments. To begin to understand the function of C1QLs, we determined high-resolution crystal structures of the globular C1q-domains of C1QL1, C1QL2, and C1QL3. Each structure is a trimer, with each protomer forming a jelly-roll fold consisting of 10 β strands. Moreover, C1QL trimers may assemble into higher-order oligomers similar to adiponectin and contain four Ca(2+)-binding sites along the trimeric symmetry axis, as well as additional surface Ca(2+)-binding sites. Mutation of Ca(2+)-coordinating residues along the trimeric symmetry axis lowered the Ca(2+)-binding affinity and protein stability. Our results reveal unique structural features of C1QLs among C1q/TNF superfamily proteins that may be associated with their specific brain functions.

PubMed: 25752542
DOI: 10.1016/j.str.2015.01.019

Experimental method

X-RAY DIFFRACTION (1.801 Å)