A NEW CRYSTAL FORM OF PENICILLIN ACYLASE FROM ESCHERICHIA-COLI

A new crystal form of penicillin acylase (penicillin amidohydrolase, E .C. 3.5.1.11) from Escherichia coli W (ATCC 11105) is reported. The cr ystals were grown using a combination of hanging-drop and streak-seedi ng methods. The crystals are in the monoclinic space group P2(1) with cell dimensions a = 51.52, b = 131.95, c = 64.43 Angstrom, beta = 106. 12 degrees. There is one heterodimer in the asymmetric unit (V-m = 2.4 5 Angstrom(3) Da(-1)) and the solvent content is 49%. Preliminary data have been collected to d(min) = 2.7 Angstrom using a MAR Research ima ge plate and a rotating-anode X-ray source. Subsequent experiments sho w diffraction beyond 1.3 Angstrom at a synchrotron radiation source.