Ra. Atkinson et al., Ca2+-independent binding of an EF-hand domain to a novel motif in the alpha-actinin-titin complex, NAT ST BIOL, 8(10), 2001, pp. 853-857
The interaction between alpha -actinin and titin, two modular muscle protei
ns, is essential for sarcomere assembly. We have solved the solution struct
ure of a complex between the calcium-insensitive C-terminal EF-hand domain
of alpha -actinin-2 and the seventh Z-repeat of titin. The structure of the
complex is in a semi-open conformation and closely resembles that of myosi
n light chains in their complexes with heavy chain IQ motifs. However, no I
Q motif is present in the Z-repeat, suggesting that the semi-open conformat
ion is a general structural solution for calcium-independent recognition of
EF-hand domains.