Crystallization and preliminary crystallographic studies of the catalytic subunits of human pyruvate dehydrogenase phosphatase isoforms 1 and 2

Pyruvate dehydrogenase phosphatase (PDP) is a mitochondrial serine phos-phatase that activates phosphorylated pyruvate dehydrogenase complex by dephosphorylation. In humans, two PDP isoforms (1 and 2) have been identified. PDP1 is composed of a catalytic subunit (PDP1c) and a regulatory subunit (PDP1r), whereas PDP2 consists of only a catalytic subunit (PDP2c). Both PDP1c and PDP2c have been crystallized individually and complete X-ray diffraction data sets have been collected to 2.45 and 2.0 Å resolution, respectively. The PDP1c crystals belonged to space group P4₁2₁2 or P4₃2₁2, with unit-cell parameters a = b = 65.1, c = 216.1 Å. The asymmetric unit is expected to contain one molecule, with a Matthews coefficient V_M of 2.56 ų Da^-1. The PDP2c crystals belonged to space group P2₁2₁2 ₁, with unit-cell parameters a = 53.6, b = 69.1, c = 109.7 Å. The asymmetric unit is expected to contain one molecule, with a Matthews coefficient V_M of 1.91 ų Da^-1.