肌动蛋白结合蛋白-肌联蛋白复合物中EF手结构域与新基序的Ca2+非依赖性结合。

Ca2+-independent binding of an EF-hand domain to a novel motif in the alpha-actinin-titin complex.

作者信息

Atkinson R A, Joseph C, Kelly G, Muskett F W, Frenkiel T A, Nietlispach D, Pastore A

机构信息

Division of Molecular Structure, National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA UK.

出版信息

Nat Struct Biol. 2001 Oct;8(10):853-7. doi: 10.1038/nsb1001-853.

DOI:10.1038/nsb1001-853

PMID:11573089

Abstract

The interaction between alpha-actinin and titin, two modular muscle proteins, is essential for sarcomere assembly. We have solved the solution structure 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 myosin light chains in their complexes with heavy chain IQ motifs. However, no IQ motif is present in the Z-repeat, suggesting that the semi-open conformation is a general structural solution for calcium-independent recognition of EF-hand domains.

摘要

α-辅肌动蛋白和肌联蛋白这两种模块化肌肉蛋白之间的相互作用对于肌节组装至关重要。我们解析了α-辅肌动蛋白-2的钙不敏感C端EF手型结构域与肌联蛋白的第七个Z重复序列之间复合物的溶液结构。该复合物的结构呈半开放构象，与肌球蛋白轻链与重链IQ模体形成的复合物结构极为相似。然而，Z重复序列中不存在IQ模体，这表明半开放构象是EF手型结构域钙非依赖性识别的一种通用结构解决方案。