Kühlbrandt Werner, Zeelen Johan, Dietrich Jens
Max-Planck-Institut für Biophysik, Heinrich-Hoffmann-Str. 7, 60528 Frankfurt am Main, Germany.
Science. 2002 Sep 6;297(5587):1692-6. doi: 10.1126/science.1072574. Epub 2002 Aug 8.
Proton pumps in the plasma membrane of plants and yeasts maintain the intracellular pH and membrane potential. To gain insight into the molecular mechanisms of proton pumping, we built an atomic homology model of the proton pump based on the 2.6 angstrom x-ray structure of the related Ca2+ pump from rabbit sarcoplasmic reticulum. The model, when fitted to an 8 angstrom map of the Neurospora proton pump determined by electron microscopy, reveals the likely path of the proton through the membrane and shows that the nucleotide-binding domain rotates by approximately 70 degrees to deliver adenosine triphosphate (ATP) to the phosphorylation site. A synthetic peptide corresponding to the carboxyl-terminal regulatory domain stimulates ATPase activity, suggesting a mechanism for proton transport regulation.
植物和酵母质膜中的质子泵维持细胞内pH值和膜电位。为深入了解质子泵的分子机制，我们基于兔肌浆网相关Ca2+泵的2.6埃X射线结构构建了质子泵的原子同源模型。该模型与通过电子显微镜确定的粗糙脉孢菌质子泵8埃图谱拟合时，揭示了质子穿过膜的可能路径，并表明核苷酸结合结构域旋转约70度以将三磷酸腺苷（ATP）递送至磷酸化位点。对应于羧基末端调节结构域的合成肽刺激ATP酶活性，提示了一种质子运输调节机制。
