α‐Actinin and spectrin structures: an unfolding family story

In red blood cells, the integrity of the spectrin network is essential for normal cell shape and elasticity. To understand the molecular basis for spectrin's mechanical properties, one must determine how spectrin subunits interact with each other. The newly described crystallographic structures of two consecutive homologous repeats of human α‐actinin, a member of the spectrin superfamily, shed new light on α‐actinin interchain binding properties. Here I present evidence that interchain binding at the tail end of the spectrin molecule is likely to occur via a mechanism similar to that observed for α‐actinin.