Purification, crystallization and preliminary X-ray crystallographic analysis of the phosphatase domain (PA3346PD) of the response regulator PA3346 from Pseudomonas aeruginosa PAO1

Abstract

The phosphatase domain (PA3346PD) of the response regulator PA3346 modulates the downstream anti-anti-σ factor PA3347 to regulate swarming motility in Pseudomonas aeruginosa PAO1. PA3346PD, which comprises the protein phosphatase 2C domain (PP2C), is classified as a Ser/Thr phosphatase of the Mg2+-or Mn2+-dependent protein phosphatase (PPM) family. The recombinant PA3346PD, with molecular mass 26 kDa, was overexpressed in Escherichia coli, purified on an Ni2+-NTA agarose column and crystallized by the sitting-drop vapour-diffusion method. X-ray diffraction data were collected from PA3346PD crystals to a resolution of 2.58 Å and the crystals belonged to space group I4132 or I4332, with unit-cell parameter a = 157.61 Å. Preliminary analysis indicates the presence of a monomer of PA3346PD in the asymmetric unit with a solvent content of 58.4%.