Atx1 is a metallochaperone protein from the yeast Saccharomyces cerevisiae (yAtx1) that plays a major role in copper homeostasis in this organism. yAtx1 functions as a copper transfer protein by shuttling copper to the secretory pathway to control intracellular copper levels. Here we describe the first crystal structures of yAtx1 that have been determined in the presence of Cu(I). The structures from two different crystal forms have been solved and refined to resolutions of 1.65 and 1.93 Å. In contrast to the previous metallated crystal structure of yAtx1 where a single Hg(II) atom was coordinated by one yAtx1 molecule, the Cu(I)-yAtx1 was crystallised as a dimer in both crystal forms, sharing one Cu(I) atom between two yAtx1 molecules. This is consistent with the crystal structure of the human homologue Cu(I)-hAtox1. Overall the structures in the two different crystal forms of Cu(I)-yAtx1 are remarkably similar to that of Cu(I)-hAtox1. However, subtle structural differences between Cu(I)-yCtr1 and Cu(I)-hAtox1 are observed in copper coordination geometries and in the conformations of Loop 2, with the latter potentially contributing to differential interactions and copper transfer mechanisms with membrane transport copper uptake systems.

Atx1是一种来自酿酒酵母的金属伴侣蛋白（yAtx1）在这种生物体中的铜稳态中起主要作用。yAtx1通过将铜穿梭到分泌途径中以控制细胞内铜水平而充当铜转移蛋白。在这里，我们描述了yAtx1的第一个晶体结构，该结构已在存在Cu（I）的情况下确定。来自两种不同晶体形式的结构已被解析并提炼为1.65和1.93Å的分辨率。与以前的yAtx1的金属化晶体结构（其中单个Hg（II）原子由一个yAtx1分子配位）相反，Cu（I）-yAtx1在两种晶型中均以二聚体形式结晶，在两者之间共享一个Cu（I）原子。两个yAtx1分子。这与人类同系物Cu（I）-hAtox1的晶体结构一致。总体而言，Cu（I）-yAtx1的两种不同晶体形式的结构与Cu（I）-hAtox1的结构极为相似。然而，在铜配位几何结构和Loop 2的构型中，观察到了Cu（I）-yCtr1和Cu（I）-hAtox1之间的细微结构差异，后者可能与膜传输铜的吸收产生不同的相互作用和铜转移机制系统。