Granzin J, Wilden U, Choe H W, Labahn J, Krafft B, Büldt G
Forschungszentrum Jülich, Institut für Biologische Informationsverarbeitung, Germany.
Nature. 1998 Feb 26;391(6670):918-21. doi: 10.1038/36147.
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 A 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 agrees with the interpretation of binding studies on partially digested and mutated arrestin.
视网膜抑制蛋白是脊椎动物视杆细胞外段光反应终止所必需的蛋白质。它通过与磷酸化的光激活视紫红质（P-Rh*）结合的能力，在淬灭光诱导的酶级联反应中发挥重要作用。抑制蛋白存在于各种G蛋白偶联的放大级联反应中。在此，我们报告了牛抑制蛋白（相对分子质量为45,300）在3.3埃分辨率下的三维结构。晶体结构由通过一个铰链区连接的两个反平行β折叠结构域以及氨基末端折叠背面的一个短α螺旋组成。如光感受器与抑制蛋白三维结构的对接所示，磷酸化光激活视紫红质的结合区域位于N末端结构域。这与对部分消化和突变的抑制蛋白的结合研究结果相符。
