2R0C

Structure of the substrate-free form of the rebeccamycin biosynthetic enzyme REBC

X-RAY DIFFRACTION

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Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1		7.4	298	1.5 microliters of RebC (9 mg/mL in 150 mM NaCl, 10% glycerol, 25 mM HEPES pH 7.5) were incubated with 0.35 microliters of guanidine-HCl for 30 seconds, followed by addition of 1.5 microliters of precipitant solution (19% PEG-8000, 0.1 M HEPES pH 7.4), without mixing, at room temperature and sealed over a precipitant well solution. Immediately after set up, crystal trays were placed on a gel shaker and then, after 12 hours, transferred to a storage space in vibration-isolation. Before being flash-frozen in liquid nitrogen, a crystal was soaked for five seconds in cryogenic solution (19% PEG-8000, 0.1 M HEPES pH 7.4, 20% glycerol), VAPOR DIFFUSION, HANGING DROP, temperature 298K, pH 7.40

Crystal Properties
Matthews coefficient	Solvent content
2.52	51.11

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 63.22	α = 90
b = 77.562	β = 108.04
c = 64.673	γ = 90

Symmetry
Space Group	P 1 21 1

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	100	CCD	MARMOSAIC 325 mm CCD	FLAT COLLIMATING MIRROR, DOUBLE CRYSTAL MONOCHROMATOR, TOROID FOCUSING MIRROR	2006-07-09	M	MAD

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	SSRL BEAMLINE BL9-2	1.8455, 1.8447, 0.9798	SSRL	BL9-2

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Sym I (Observed)	Net I Over Average Sigma (I)	Redundancy	Number Reflections (All)	Number Reflections (Observed)	Observed Criterion Sigma (F)	Observed Criterion Sigma (I)	B (Isotropic) From Wilson Plot
1	1.8	50	93.9	0.09	25.4	7.2		52005

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R-Sym I (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
	1.8	1.86	67.2		0.458	2.6

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Resolution (High)	Resolution (Low)	Number Reflections (All)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MAD	THROUGHOUT	1.8	50	55046	51814	2566	94.1	0.211	0.211	0.241	RANDOM	41.7

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]
4.011		5.453	-15.012		11.001

RMS Deviations
Key	Refinement Restraint Deviation
c_scangle_it	2.877
c_mcangle_it	2.194
c_scbond_it	1.976
c_mcbond_it	1.447
c_angle_deg	1.28
c_bond_d	0.006
c_bond_d_na
c_bond_d_prot
c_angle_d
c_angle_d_na
c_angle_d_prot
c_angle_deg_na
c_angle_deg_prot
c_dihedral_angle_d
c_dihedral_angle_d_na
c_dihedral_angle_d_prot
c_improper_angle_d
c_improper_angle_d_na
c_improper_angle_d_prot

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	3898
Nucleic Acid Atoms
Solvent Atoms	427
Heterogen Atoms	54

Software

Software
Software Name	Purpose
HKL-2000	data collection
SHARP	phasing
CNS	refinement
HKL-2000	data reduction
SCALEPACK	data scaling