ジャーナル: Structure / 年: 2016 タイトル: Structures of Human Peroxiredoxin 3 Suggest Self-Chaperoning Assembly that Maintains Catalytic State. 著者: N Amy Yewdall / Hariprasad Venugopal / Ambroise Desfosses / Vahid Abrishami / Yuliana Yosaatmadja / Mark B Hampton / Juliet A Gerrard / David C Goldstone / Alok K Mitra / Mazdak Radjainia / 要旨: Peroxiredoxins are antioxidant proteins primarily responsible for detoxification of hydroperoxides in cells. On exposure to various cellular stresses, peroxiredoxins can acquire chaperone activity, ...Peroxiredoxins are antioxidant proteins primarily responsible for detoxification of hydroperoxides in cells. On exposure to various cellular stresses, peroxiredoxins can acquire chaperone activity, manifested as quaternary reorganization into a high molecular weight (HMW) form. Acidification, for example, causes dodecameric rings of human peroxiredoxin 3 (HsPrx3) to stack into long helical filaments. In this work, a 4.1-Å resolution structure of low-pH-instigated helical filaments was elucidated, showing a locally unfolded active site and partially folded C terminus. A 2.8-Å crystal structure of HsPrx3 was determined at pH 8.5 under reducing conditions, wherein dodecameric rings are arranged as a short stack, with symmetry similar to low-pH filaments. In contrast to previous observations, the crystal structure displays both a fully folded active site and ordered C terminus, suggesting that the HsPrx3 HMW form maintains catalytic activity. We propose a new role for the HMW form as a self-chaperoning assembly maintaining HsPrx3 function under stress.
解像度: 2.8→52.27 Å / Cor.coef. Fo:Fc: 0.929 / Cor.coef. Fo:Fc free: 0.901 / SU B: 14.847 / SU ML: 0.275 / 交差検証法: THROUGHOUT / σ(F): 0 / ESU R: 1.085 / ESU R Free: 0.317 詳細: HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS U VALUES : REFINED INDIVIDUALLY