Crystallization and preliminary X-ray diffraction analysis of full-length and proteolytically activated pyruvate oxidase from Escherichia coli.

The thiamine diphosphate- and flavin-dependent peripheral membrane enzyme pyruvate oxidase from Escherichia coli (EcPOX) has been crystallized in the full-length form and as a proteolytically activated C-terminal truncation variant which lacks the last 23 amino acids (Delta23 EcPOX). Crystals were grown by the hanging-drop vapour-diffusion method using either protamine sulfate (full-length EcPOX) or 2-methyl-2,4-pentanediol (Delta23 EcPOX) as precipitants. Native data sets were collected at a X-ray home source to a resolution of 2.9 A. The two forms of EcPOX crystallize in different space groups. Whereas full-length EcPOX crystallizes in the tetragonal space group P4(3)2(1)2 with two monomers per asymmetric unit, the crystals of Delta23 EcPOX belong to the orthorhombic space group P2(1)2(1)2(1) and contain 12 monomers per asymmetric unit.