4A01

Crystal Structure of the H-Translocating Pyrophosphatase

4A01 の概要

• エントリーDOI: 10.2210/pdb4a01/pdb
• 分子名称: PROTON PYROPHOSPHATASE, MAGNESIUM ION, POTASSIUM ION, ... (6 entities in total)
• 機能のキーワード: hydrolase, membrane protein, proton pumping
• 由来する生物種: VIGNA RADIATA
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 165203.94

構造登録者

Lin, S.-M.,Tsai, J.-Y.,Hsiao, C.-D.,Chiu, C.-L.,Pan, R.-L.,Sun, Y.-J. (登録日: 2011-09-07, 公開日: 2012-03-28, 最終更新日: 2024-11-13)

主引用文献

Lin, S.-M.,Tsai, J.-Y.,Hsiao, C.-D.,Chiu, C.-L.,Pan, R.-L.,Sun, Y.-J.
Crystal Structure of a Membrane Embedded H1-Translocating Pyrophosphatase
Nature, 484:399-, 2012

PubMed Abstract: H(+)-translocating pyrophosphatases (H(+)-PPases) are active proton transporters that establish a proton gradient across the endomembrane by means of pyrophosphate (PP(i)) hydrolysis. H(+)-PPases are found primarily as homodimers in the vacuolar membrane of plants and the plasma membrane of several protozoa and prokaryotes. The three-dimensional structure and detailed mechanisms underlying the enzymatic and proton translocation reactions of H(+)-PPases are unclear. Here we report the crystal structure of a Vigna radiata H(+)-PPase (VrH(+)-PPase) in complex with a non-hydrolysable substrate analogue, imidodiphosphate (IDP), at 2.35 Å resolution. Each VrH(+)-PPase subunit consists of an integral membrane domain formed by 16 transmembrane helices. IDP is bound in the cytosolic region of each subunit and trapped by numerous charged residues and five Mg(2+) ions. A previously undescribed proton translocation pathway is formed by six core transmembrane helices. Proton pumping can be initialized by PP(i) hydrolysis, and H(+) is then transported into the vacuolar lumen through a pathway consisting of Arg 242, Asp 294, Lys 742 and Glu 301. We propose a working model of the mechanism for the coupling between proton pumping and PP(i) hydrolysis by H(+)-PPases.

PubMed: 22456709
DOI: 10.1038/NATURE10963

実験手法

X-RAY DIFFRACTION (2.35 Å)