CRYSTALLIZATION AND PRELIMINARY CRYSTALLOGRAPHIC ANALYSIS OF REPA1, AREPLICATION CONTROL PROTEIN OF THE REPFIC REPLICON OF ENTEROTOXIN PLASMID ENTP307

RepA1 protein is essential for replication of the RepFIC replicon of e nterotoxin plasmid EntP307 and is thought to interact directly with th e origin of replication. We have purified RepA1 from an over-producing expression system and have prepared single crystals using a macroseed ing technique. The crystals belong to space group P2(1)2(1)2(1) or P2( 1)2(1)2, with cell dimensions a = 61 Angstrom, b = 67 Angstrom, and c = 243 Angstrom. They diffract X-rays to 3.3 Angstrom resolution and pr obably contain two 40,000 molecular weight RepA1 molecules per asymmet ric unit. (C) 1996 Wiley-Liss, Inc.