Human dystrophin tandem calponin homology actin-binding domain crystallized in a closed-state conformation.

Publication Type:

Journal Article

Authors:

Streeter, Oakley; Shi, Ke; Vavra, Joseph; Aihara, Hideki; Ervasti, James M; Evans, Robert; Muretta, Joseph M

Source:

Acta Crystallogr D Struct Biol, Volume 81, Issue Pt 3, p.122-129 (2025)

Keywords:

Actins, Binding Sites, Calcium-Binding Proteins, Calponins, Crystallography, X-Ray, Dystrophin, Humans, Microfilament Proteins, Models, Molecular, Protein Binding, Protein Conformation, Protein Domains

Abstract:

<p>The structure of the N-terminal actin-binding domain of human dystrophin was determined at 1.94 Å resolution. Each chain in the asymmetric unit exists in a `closed&#39; conformation, with the first and second calponin homology (CH) domains directly interacting via a 2500.6 Å interface. The positioning of the individual CH domains is comparable to the domain-swapped dimer seen in previous human dystrophin and utrophin actin-binding domain 1 structures. The CH1 domain is highly similar to the actin-bound utrophin structure and structural homology suggests that the `closed&#39; single-chain conformation opens during actin binding to mitigate steric clashes between CH2 and actin.</p>