한빛사논문
Md. Murad Khan1,†, Seowon Lee2,†, Sergio Couoh-Cardel1,†,‡, Rebecca A Oot1, Hyunmin Kim2, Stephan Wilkens1,* & Soung-Hun Roh2,*
1 Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
2 School of Biological Science, Institute of Molecular Biology and Genetics, Seoul National University, Seoul, South Korea
*Corresponding author.
†These authors contributed equally to this work.
‡Present address: Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
Abstract
The vacuolar ATPase (V-ATPase) is a rotary motor proton pump that is regulated by an assembly equilibrium between active holoenzyme and autoinhibited V1-ATPase and Vo proton channel subcomplexes. Here, we report cryo-EM structures of yeast V-ATPase assembled in vitro from lipid nanodisc reconstituted Vo and mutant V1. Our analysis identified holoenzymes in three active rotary states, indicating that binding of V1 to Vo provides sufficient free energy to overcome Vo autoinhibition. Moreover, the structures suggest that the unequal spacing of Vo’s proton-carrying glutamic acid residues serves to alleviate the symmetry mismatch between V1 and Vo motors, a notion that is supported by mutagenesis experiments. We also uncover a structure of free V1 bound to Oxr1, a conserved but poorly characterized factor involved in the oxidative stress response. Biochemical experiments show that Oxr1 inhibits V1-ATPase and causes disassembly of the holoenzyme, suggesting that Oxr1 plays a direct role in V-ATPase regulation.
논문정보
관련 링크
연구자 ID
관련분야 연구자보기
소속기관 논문보기
관련분야 논문보기
해당논문 저자보기