Structural Study of Human Mitochondrial Respiratory Chain


题 目:Structural Study of Human Mitochondrial Respiratory Chain

报告人:杨茂君 教授,清华大学生命科学学院

时 间:2017年9月15日(周五)下午 4:00

地 点:药学院至诚楼310报告厅

主 持:李仲 教授

The respiratory megacomplex represents the highest-order assembly of respiratory chain complexes, and it allows mitochondrial to respond to energy-requiring conditions. To understand its architecture, we examined the human respiratory chain megacomplex-I2III2IV2 (MCI2III2IV2) with 140 subunits and a subset of associated cofactors using cryo-electron microscopy. The MCI2III2IV2 forms a circular structure with the dimeric CIII located in the center, where it is surrounded by two copies each of CI and CIV. Two cytochrome c (Cyt.c) molecules are positioned to accept electrons on the surface of the c1 state CIII dimer. Analyses indicate that CII could insert into the  gaps between CI and CIV to form a closed ring, which we termed the electron transport chain supercomplex. The structure not only reveals the precise assignment of individual subunits of human CI and CIII, but also enables future in-depth analysis of the electron  transport chain as a whole.