Crystallization and preliminary X-ray analysis of β -hydroxydecanoyl thiol ester dehydrase from Escherichia coli^*

Abstract

Escherichia coli β -hydroxydecanoyl thiol ester dehydrase, a key enzyme for the biosynthesis of unsaturated fatty acids in E. coli, has been crystallized by the vapor diffusion method at pH 5.0-5.5 using 20% (w/v) polyethylene glycol (molecular weight 8000) as a precipitant. Two crystal forms have been characterized, and both diffract to at least 1.6 Å . The orthorhombic crystals belong to space group P2₁2₁2₁, with cell constants of a = 68.4 Å , b = 87.3 Å , and c = 60.3 Å . Monoclinic crystals are of space group C2, with a = 131.9 Å, b = 71.5 Å, c = 92.5 Å, and β = 103.5 °.