CRYSTAL-STRUCTURE OF AN N-TERMINAL FRAGMENT OF THE DNA GYRASE B-PROTEIN

The crystal structure of an N-terminal fragment of the Escherichia coli DNA gyrase B protein, complexed with a nonhydrolysable ATP analogue, has been solved at 2.5 angstrom resolution. It consists of two domains, both containing novel protein folds. The protein fragment forms a dimer, whose N-terminal domains are responsible for ATP binding and hydrolysis. The C-terminal domains form the sides of a 20 angstrom hole through the protein dimer which may play a role in DNA strand passage during the supercoiling reaction.