Alpha-actinin can cross-link actin filaments and anchor them to the Z-disk in sarcomeres. Sarcomeres are a structural unit of myofibril in striated muscle. The FATZ (filamin, α-actinin- and telethonin-binding protein of the Z-disk) protein can interact with α-actinin and other core Z-disk proteins that contribute to myofibril assembly and maintenance. In a new report now on Science Advances, Antonio Sponga and an international research team in Austria, Germany, Russia, Poland and the U.K. detailed the first structure and cellular validation of the α-actinin-2 complex with a Z-disk partner, FATZ-1, to form a conformal ensemble. The FATZ-1 formed a tight fuzzy complex with α-actinin-2 with a proposed interaction mechanism via molecular recognition elements and secondary binding sites. The obtained integrative model revealed a polar architecture of the complex in combination with the FATZ-1 multivalent scaffold function to organize interaction partners and stabilize.