Crystal structure of a rigid four-spectrin-repeat fragment of the human desmoplakin plakin domain.
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Choi HJ, Weis WI
Crystal structure of a rigid four-spectrin-repeat fragment of the human desmoplakin plakin domain.
J Mol Biol. 2011 Jun 24;409(5):800-12. doi: 10.1016/j.jmb.2011.04.046. Epub 2011 Apr 22.
- PubMed ID
- 21536047 [ View in PubMed]
- Abstract
The plakin protein family serves to connect cell-cell and cell-matrix adhesion molecules to the intermediate filament cytoskeleton. Desmoplakin (DP) is an integral part of desmosomes, where it links desmosomal cadherins to the intermediate filaments. The 1056-amino-acid N-terminal region of DP contains a plakin domain common to members of the plakin family. Plakin domains contain multiple copies of spectrin repeats (SRs). We determined the crystal structure of a fragment of DP, residues 175-630, consisting of four SRs and an inserted SH3 domain. The four repeats form an elongated, rigid structure. The SH3 domain is present in a loop between two helices of an SR and interacts extensively with the preceding SR in a manner that appears to limit inter-repeat flexibility. The intimate intramolecular association of the SH3 domain with the preceding SR is also observed in plectin, another plakin protein, but not in alpha-spectrin, suggesting that the SH3 domain of plakins contributes to the stability and rigidity of this subfamily of SR-containing proteins.