9T99

Structure of C. elegans Dicer-related helicase 1 (DRH1) bound to blunt end 5'P-dsRNA

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	SYNCHROTRON
Source details	ESRF BEAMLINE ID29
Synchrotron site	ESRF
Beamline	ID29
Temperature [K]	100
Detector technology	PIXEL
Collection date	2016-11-20
Detector	DECTRIS PILATUS 6M
Wavelength(s)	0.97931
Spacegroup name	I 41 2 2
Unit cell lengths	134.354, 134.354, 221.301
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	72.080 - 2.180
R-factor	0.2199
Rwork	0.218
R-free	0.25690
Structure solution method	MOLECULAR REPLACEMENT
RMSD bond length	0.003
RMSD bond angle	0.500
Data reduction software	autoPROC
Data scaling software	STARANISO
Phasing software	MOLREP
Refinement software	PHENIX (1.21.1_5286)

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	114.846	2.335
High resolution limit [Å]	2.180	2.180
Rmerge	0.075	1.549
Rmeas	0.087
Rpim	0.037
Number of reflections	44595	2232
<I/σ(I)>	11	1.5
Completeness [%]	84.2	23
Redundancy	5	5.4
CC(1/2)	0.999	0.514

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION, SITTING DROP		277	Directly after size exclusion chromatography DRH-1deltaN_E431Q was concentrated 10 mg/ml and mixed with 12 dsRNAp in a 1:2 molar ratio, ADP-AlF4 (adenosine-5-diphosphate with aluminium fluoride) and 2 mM MgCl2 were added then incubated for 30 minutes on ice. The complex was mixed with reservoir buffer (0.2 M tri Ammonium citrate 20 % PEG3350 or 0.2 M Sodium malonate dibasic monohydrate 20% PEG3350) in 1:1 ratio. Crystals grew in two weeks at 4 C.