X-ray crystal structure of arrestin from bovine rod outer segments
X-ray crystal structure of arrestin from bovine rod outer segments
复制标题
作者：
Granzin, J;Wilden, U;Büldt, G
视网膜arrestin是脊椎动物视杆外节终止光反应所必需的蛋白质。它通过与磷酸化的光激活视紫红质(P-Rh*)结合，在猝灭光诱导酶的级联反应中起着重要作用。在不同的G蛋白偶联扩增级联反应中都发现了抑制素。在这里，我们报道了牛Arrestin(相对分子质量，45,300)在3.3埃分辨率下的三维结构。晶体结构包括通过铰链区连接的两个反平行的β-折叠结构域和氨基末端折叠背面的一个短的α-螺旋。光激活视紫红质的结合区域位于N-末端结构域，光感受器与arrestin的三维结构的对接表明。这与部分消化和突变的arrestin的结合研究的解释一致。
Retinal arrestin is the essential protein for the termination of the light response in vertebrate rod outer segments. It plays an important role in quenching the light-induced enzyme cascade by its ability to bind to phosphorylated light-activated rhodopsin (P-Rh*). Arrestins are found in various G-protein-coupled amplification cascades. Here we report on the three-dimensional structure of bovine arrestin (relative molecular mass, 45,300) at 3.3 Angstrom resolution. The crystal structure comprises two domains of antiparallel beta-sheets connected through a hinge region and one short alpha-helix on the back of the amino-terminal fold. The binding region for phosphorylated light-activated rhodopsin is located at the N-terminal domain, as indicated by the docking of the photoreceptor to the three-dimensional structure of arrestin. This ag rees with the interpretation of binding studies on partially digested and mutated arrestin.