2OCW

Solution structure of human secretory component

Summary for 2OCW

• Entry DOI: 10.2210/pdb2ocw/pdb
• Related: 1iga 1r70
• Descriptor: Polymeric-immunoglobulin receptor (1 entity in total)
• Functional Keywords: sc, immunoglobulin, secretory, antibody, immunity, immune system
• Biological source: Homo sapiens (human)
• Cellular location: Cell membrane; Single-pass type I membrane protein. Secretory component: Secreted: P01833
• Total number of polymer chains: 1
• Total formula weight: 64355.23

Authors

Bonner, A.,Perrier, C.,Corthesy, B.,Perkins, S.J. (deposition date: 2006-12-21, release date: 2007-04-10, Last modification date: 2023-12-27)

Primary citation

Bonner, A.,Perrier, C.,Corthesy, B.,Perkins, S.J.
Solution structure of human secretory component and implications for biological function.
J.Biol.Chem., 282:16969-16980, 2007

PubMed Abstract: Secretory component (SC) in association with polymeric IgA (pIgA) forms secretory IgA, the major antibody active at mucosal surfaces. SC also exists in the free form, with innate-like neutralizing properties against pathogens. Free SC consists of five glycosylated variable (V)-type Ig domains (D1-D5), whose structure was determined by x-ray and neutron scattering, ultracentrifugation, and modeling. With a radius of gyration of 3.53-3.63 nm, a length of 12.5 nm, and a sedimentation coefficient of 4.0 S, SC possesses an unexpected compact structure. Constrained scattering modeling based on up to 13,000 trial models shows that SC adopts a J-shaped structure in which D4 and D5 are folded back against D2 and D3. The seven glycosylation sites are located on one side of SC, leaving known IgA-binding motifs free to interact with pIgA. This work represents the first analysis of the three-dimensional structure of full-length free SC and paves the way to a better understanding of the association between SC and its potential ligands, i.e. pIgA and pathogenic-associated motifs.

PubMed: 17428798
DOI: 10.1074/jbc.M701281200

Experimental method

SOLUTION SCATTERING