Crystallization of the Bacillus subtilis RTP-DNA complex prepared using NMR spectroscopy

The replication terminator protein (RTP)-DNA complex of Bacillus subtilis i s responsible for the arrest of DNA replication at terminator sites in the B. subtilis chromosome. The crystallization and preliminary diffraction dat a analysis for the complex of an N-15-labelled mutant form of RTP and a sym metrical form of its DNA-binding site is reported. NMR spectroscopy was use d to assess the stoichiometry of complex formation, with the sample contain ing the most homogenous solution of complex giving rise to diffracting crys tals. Synchrotron-radiation data to 2.5 Angstrom were collected from a crys tal of space group P3(2)21, unit-cell parameters a = b = 44.780, c = 395.58 2 Angstrom, containing an RTP dimer within the asymmetric unit.