Cloning, purification, crystallization and preliminary X-ray crystallographic analysis of MCAT from Staphylococcus aureus.

Malonyl-CoA:acyl-carrier protein transacylase (MCAT), encoded by the fabd gene, is a key enzyme in type II fatty-acid biosynthesis. It is responsible for transferring the malonyl group from malonyl-CoA to the holo acyl-carrier protein (ACP). Since the type II system differs from the type I system that mammals use, it has received enormous attention as a possible antibiotic target. In particular, only a single isoform of MCAT has been reported and a continuous coupled enzyme assay has been developed. MCAT from Staphylococcus aureus was overexpressed in Escherichia coli and the protein was purified and crystallized. Diffraction data were collected to 1.2 A resolution. The crystals belonged to space group P2(1), with unit-cell parameters a = 41.608, b = 86.717, c = 43.163 A, alpha = gamma = 90, beta = 106.330 degrees . The asymmetric unit contains one SaMCAT molecule.