Crystallization and preliminary X-ray analysis of the C-terminal RNase III domain of human Dicer

Human Dicer protein contains two RNase III domains ( RNase IIIa and RNase IIIb) which are involved in the production of short interfering RNAs (siRNAs). The C-terminal RNase III domain ( RNase IIIb) of human Dicer was expressed, purified and crystallized by the sitting-drop vapour-diffusion method. The crystals belonged to space group C222(1), with unit-cell parameters a = 88.6, b = 199.7, c = 119.6 angstrom, and diffracted X-rays to 2.0 angstrom resolution. The asymmetric unit contained three molecules of the RNase IIIb and the solvent content was 67%.