An outstanding research paper entitled “Crystal structure of a membrane-embedded H+-translocating pyrophosphatase” in Nature was performed by Prof. Yuh-Ju Sun’s research team at Institute of Bioinformatics and Structural Biology, National Tsing Hua University. The team successfully determined the molecular structure of mung beans’ proton transportation of H+-translocating pyrophosphatases at resolution 2.35 Å, using high-quality and high-intensity beamlines (13B1 and 13C1) at NSRRC, and the technique of X-ray crystallography diffraction. The structure presents the state of a pyrophosphate hydrolase enzyme binding to a chemical compound, iminodiacetic phosphate. Proton translocation of H+-translocating pyrophosphatases forms dimer. Each subunit is composed of sixteen transmembrane helices. Six highly conservative core transmembrane helices at the center formed a high acidic substrate binding region. A unique pathway of proton transfering is found in its transmembrane segment.
This research team proposed the reaction mechanism of the coupling between pyrophosphate hydrolysis and proton transfer.