“…Z-repeats bind to EF-hand motifs 3-4 of the C-terminal calmodulin-like domain (CaM) of α-actinin (Atkinson et al, 2001). The interaction of Z-repeats with α-actinin has been studied in detail at the cellular, biochemical, biophysical and structural level, confirming and characterising the interaction of the helical Z-repeats with the α-actinin CaM domain (Atkinson et al, 2000(Atkinson et al, , 2001Ribeiro et al, 2014;Sorimachi et al, 1997;Young et al, 1998). There is a strict correlation of the number of titin Z-repeats with the number of Z-links: chicken pectoralis major muscle, a fast glycolytic muscle with thin Z-disks, expresses titin with two Z-repeats (Peckham et al, 1997), while cardiac and slow skeletal muscles in mammals with thick Z-disks express up to seven Z-repeats Sorimachi et al, 1997).…”