Purification and crystallization of RNase HIII from Staphylococcus aureus

As part of collaborative efforts to characterize virulence factors from Staphylococcus aureus, methods for the large-scale recombinant production of RNase HIII from S. aureus subspecies MRSA252 (Sa-RNase HIII) have been developed. RNase HIII-type ribonucleases are poorly characterized members of the RNase H group of endonucleases which hydrolyze RNA from RNA/DNA hybrids and are thought to be involved in DNA replication and repair. They are characterized by N-terminal extensions of unknown function that do not share sequence homology with the N-terminal extensions of bacterial RNases HI and RNases HII. Sa-RNase HIII was crystallized in the orthorhombic space group P2₁2₁2₁, with unit-cell parameters a = 48.9, b = 74.2, c = 127.5 Å, and diffracted to 2.6 Å resolution.