Purification, crystallization and preliminary X-ray analysis of the novel DEAD protein RstDEAD from Bacillus stearothermophilus

DEAD proteins are members of a large and diverse family of RNA helicases that use energy from ATP hydrolysis to unwind short regions of duplex RNA. BstDEAD from Bacillus stearothermophilus is a 436-amino-acid protein and a representative member of the DEAD protein family. In addition to the mechanistic core common to DEAD proteins, BstDEAD has a unique similar to60-amino-acid C-terminal extension that may denote a specific biological role. BstDEAD has been crystallized in space group P4(1)/32(1)2, with unit-cell parameters a = b = 100.3, c = 110.6 Angstrom and one molecule per asymmetric unit. It is the first DEAD protein to be crystallized containing a unique extension outside of the core.