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 phosphatase 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 A resolution, respectively. The PDP1c crystals belonged to space group P4(1)2(1)2 or P4(3)2(1)2, with unit-cell parameters a = b = 65.1, c = 216.1 A. The asymmetric unit is expected to contain one molecule, with a Matthews coefficient V(M) of 2.56 A(3) Da(-1). The PDP2c crystals belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 53.6, b = 69.1, c = 109.7 A. The asymmetric unit is expected to contain one molecule, with a Matthews coefficient V(M) of 1.91 A(3) Da(-1).