Crystallization and preliminary X-ray analysis of Escherichia coli methionyl-tRNA(f)(Met) formyltransferase complexed with formyl-methionyl-tRNA(f)(Met)

The structure of methionyl-tRNA(f)(Met) formyltransferase from E. coli, a m onomeric protein of 34 kDa, has previously been determined at 2.0 Angstrom resolution. In the present work, this enzyme was crystallized as a complex with its macromolecular product, the initiator formyl-methionyl-tRNA(f)(Met ) (25 kDa). Polyethylene glycol 5000 monomethyl-ether was used as a precipi tating agent. The crystals are orthorhombic and have unit-cell parameters a = 201.7, b = 68.1, c = 86.4 Angstrom. They belong to space group P2(1)2(1) 2 and diffract to 2.8 Angstrom resolution. The structure is being solved wi th the help of a mercury derivative.