223D

DIRECT OBSERVATION OF TWO BASE-PAIRING MODES OF A CYTOSINE-THYMINE ANALOGUE WITH GUANINE IN A DNA Z-FORM DUPLEX: SIGNIFICANCE FOR BASE ANALOGUE MUTAGENESIS

X-RAY DIFFRACTION

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Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION	6.5	277	pH 6.50, VAPOR DIFFUSION, temperature 277.00K

Crystal Properties
Matthews coefficient	Solvent content
1.65	25.44

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 18.23	α = 90
b = 30.63	β = 90
c = 43.78	γ = 90

Symmetry
Space Group	P 21 21 21

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	292	DIFFRACTOMETER	RIGAKU AFC-5R

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	ROTATING ANODE	RIGAKU RU200

Refinement

Statistics
Diffraction ID	Structure Solution Method	Starting model	Resolution (High)	Resolution (Low)	Cut-off Sigma (F)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (Observed)	R-Work	R-Free	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	ZDF002	1.7	8	4	2798		100	0.179

Temperature Factor Modeling
Anisotropic B[1][1]	Anisotropic B[1][2]	Anisotropic B[1][3]	Anisotropic B[2][2]	Anisotropic B[2][3]	Anisotropic B[3][3]

RMS Deviations
Key	Refinement Restraint Deviation
n_phos_bond_it	10.38
n_phos_angle_it	7.71
n_sugar_angle_it	5.74
n_sugar_bond_it	4.79
n_multtor_nbd	0.278
n_singtor_nbd	0.145
n_chiral_restr	0.138
n_sugar_bond_angle_d	0.076
n_phos_bond_d	0.071
n_phos_bond_angle_d	0.048
n_plane_restr	0.044
n_sugar_bond_d	0.041
n_bond_d
n_angle_d
n_planar_d
n_hb_or_metal_coord
n_bond_angle_restr
n_dihedral_angle_restr
n_impr_tor
n_xhyhbond_nbd

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms
Nucleic Acid Atoms	240
Solvent Atoms	51
Heterogen Atoms	6

Software

Software
Software Name	Purpose
MERLOT	phasing
NUCLSQ	refinement