3DMK

Crystal structure of Down Syndrome Cell Adhesion Molecule (DSCAM) isoform 1.30.30, N-terminal eight Ig domains

Summary for 3DMK

• Entry DOI: 10.2210/pdb3dmk/pdb
• Related: 2V5M 2V5R 2V5S
• Related PRD ID: PRD_900017
• Descriptor: Down Syndrome Cell Adhesion Molecule (DSCAM) isoform 1.30.30, N-terminal eight Ig domains, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (5 entities in total)
• Functional Keywords: ig domains, immunoglobulin domain, cell adhesion
• Biological source: Drosophila melanogaster
• Total number of polymer chains: 3
• Total formula weight: 273861.58

Authors

Sawaya, M.R.,Wojtowicz, W.M.,Eisenberg, D.,Zipursky, S.L. (deposition date: 2008-07-01, release date: 2008-10-07, Last modification date: 2024-11-20)

Primary citation

Sawaya, M.R.,Wojtowicz, W.M.,Andre, I.,Qian, B.,Wu, W.,Baker, D.,Eisenberg, D.,Zipursky, S.L.
A double S shape provides the structural basis for the extraordinary binding specificity of Dscam isoforms.
Cell(Cambridge,Mass.), 134:1007-1018, 2008

PubMed Abstract: Drosophila Dscam encodes a vast family of immunoglobulin (Ig)-containing proteins that exhibit isoform-specific homophilic binding. This diversity is essential for cell recognition events required for wiring the brain. Each isoform binds to itself but rarely to other isoforms. Specificity is determined by "matching" of three variable Ig domains within an approximately 220 kD ectodomain. Here, we present the structure of the homophilic binding region of Dscam, comprising the eight N-terminal Ig domains (Dscam(1-8)). Dscam(1-8) forms a symmetric homodimer of S-shaped molecules. This conformation, comprising two reverse turns, allows each pair of the three variable domains to "match" in an antiparallel fashion. Structural, genetic, and biochemical studies demonstrate that, in addition to variable domain "matching," intramolecular interactions between constant domains promote homophilic binding. These studies provide insight into how "matching" at all three pairs of variable domains in Dscam mediates isoform-specific recognition.

PubMed: 18805093
DOI: 10.1016/j.cell.2008.07.042

Experimental method

X-RAY DIFFRACTION (4.19 Å)