Desmoplakin (DP) is an integral part of desmosomes, where it links desmosomal cadherins to the intermediate filaments. The 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) Pfam:PF00435. Spectrin repeats (SRs) consist of three alpha-helices (A, B, and C) that form an antiparallel triple-helical bundle. This entry describes SR6 which has a divergent structure relative to the other SRs. SR6 shows significant deviations in helices A and B where they are significantly shorter than in other repeats. Structural comparison revealed that SR6 is more similar to other three-helix-bundle proteins, including target of Myb1 and the syntaxin Habc domain, than to other SR proteins. Due to these differences with other spectrin repeats, this region is termed spectrin-like repeat [1].

1: Crystal structure of a rigid four-spectrin-repeat fragment of the human desmoplakin plakin domain. Choi HJ, Weis WI; J Mol Biol. 2011;409:800-812. PMID:21536047