Isolation of a DNA-binding protein from Deinococcus radiodurans having an affinity for a Z-form polynucleotide

A protein which preferentially binds Z-form duplex DNA has been purified from the cells of Deinococcus radiodurans. The molecular weight of the protein was estimated to be approximately 68,000 by gel filtration and SDS-polyacrylamide gel electrophoresis. Amino acid analysis of the protein indicates that it is not so basic since it contains a lower mole percent of lysine and higher mole percent of aspartic acid than those in histone-like DNA binding protein II (HU) of Escherichia coli. The first fifteen amino acid residues from the N-terminus have been also determined.