Structural and biochemical characterization of inorganic pyrophosphatase from Homo sapiens
- Biochem Biophys Res Commun. 2020 Dec 17;533(4):1115-1121. doi: 10.1016/j.bbrc.2020.09.139.
- 1. Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China.
- 2. Public Technology Service Center, Fujian Medical University, Fuzhou, China.
- 3. Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China.
- 4. Key Laboratory of Gastrointestinal Cancer (Fujian Medical University), Ministry of Education, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China; Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China. Electronic address: [email protected].
Inorganic pyrophosphatase (PPase) plays an essential role in energy conservation and provides energy for many biosynthetic pathways. Here, we present two three-dimensional structures of PPase from Homo sapiens (Hu-PPase) at 2.38 Å and 3.40 Å in different crystallization conditions. One of the Hu-PPase structures complex of two magnesium metal ions was determined to be a monomer (Hu-PPase-mono) here, while the other one to be a dimer-dimer (Hu-PPase-dd). In each asymmetric unit of Hu-PPase-mono, there are four α-helices and ten β-strands and folds as a barrel structure, and the active site contains two magnesium ions. Like PPases from many species, we found that Hu-PPase was able to undergo self-assembly. To our surprise, disruption of the self-assembly of Hu-PPase did not influence its enzymatic activity or the ability to promote cell growth. Our work uncovered that different structure forms of Hu-PPase and found that the pyrophosphatase activity of Hu-PPase is independent of its self-assembly.