DEAD-box helicases are enzymes with an ATP-dependent RNA-unwinding function that are involved in a variety of cellular processes including RNA splicing, ribosome biogenesis and RNA degradation. In this study, the N-terminal domain of DEAD-box RNA helicase from Staphylococcus aureus strain Mu50 was overexpressed in Escherichia coli, purified and crystallized. Diffraction data were collected to 2.60 Å resolution using a synchrotron-radiation source. The crystal belonged to space group P1, with unit-cell parameters a=70.81, b=80.23, c=86.25 Å, α=69.54, β=66.54, γ=87.32°. The unit cell contained six molecules, with a corresponding VM of 2.91 Å3 Da(-1) and a solvent content of 56.1%.