PMID: 33036755

Authors:

Hu F, Huang Z, Zheng S, Wu Q, Chen Y, Lin H, Huang W, Li L

Title:

Structural and biochemical characterization of inorganic pyrophosphatase from Homo sapiens.

Journal:

Biochem Biophys Res Commun. 2020 Oct 6. pii: S0006-291X(20)31891-X. doi:, 10.1016/j.bbrc.2020.09.139.

Abstract:

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 A and 3.40 A 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 alpha-helices and ten beta-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.