Inorganic pyrophosphatase (PPase) from a higher plant

Arabidopsis thaliana inorganic pyrophosphatase (AtPPA1) coding DNA (ppa1 gene) was cloned into bacterial expression

vector and overproduced in E. Coli cells as a His-tagged protein. The recombinant protein was purified

from the bacterial lysate by two consecutive chromatographic steps: chelating chromatography on Ni²⁺-charged

resin followed by FPLC size exclusion chromatography. The homogenous protein was submitted for crystallization.

X-Ray diffraction data extending to 1.9Å resolution were collected using synchrotron radiation. The structure

was solved by molecular replacement and refinement is in progress (R-factor below 20%). The structure of

AtPP1 represents an alpha+beta protein fold which overlaps with other structural models for known bacterial and

yeast inorganic pyrophosphatases.