2OWO

Last Stop on the Road to Repair: Structure of E.coli DNA Ligase Bound to Nicked DNA-Adenylate

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	1TA8	1. EfaLigA (aa 71-317 from PDB 1TA8) 2. TfiLigA (aa 433-584 and 321-391 from PDB 1V9P)
experimental model	PDB	1V9P	1. EfaLigA (aa 71-317 from PDB 1TA8) 2. TfiLigA (aa 433-584 and 321-391 from PDB 1V9P)

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, SITTING DROP	6	295	EcoLigA (0.3 mM) was reacted with 5 mM MgCl2 and 0.3 mM NAD+ for 30 min at 22 C. The ligase-adenylylation reaction was then quenched by adding 10 mM EDTA. The mixture was supplemented with 26-bp nicked duplex DNA (0.318 mM). This LigA-nucleic acid solution was mixed 1:2 with a well solution containing 200 mM ammonium sulfate, 50 mM sodium acetate, 24% PEG-4000. Crystals were grown at 22 C by the sitting drop vapor diffusion method. Crystals appeared after 3 days. The crystals were transferred serially to solutions containing 5% glycerol/24% PEG-4000, 10% glycerol/26% PEG-4000, 15% glycerol/28% PEG-4000, and 20% glycerol/30% PEG-4000 in 100 mM ammonium sulfate, 50 mM sodium acetate, after which they were flash-frozen in liquid nitrogen. , pH 6.0, VAPOR DIFFUSION, SITTING DROP, temperature 295K

Crystal Properties
Matthews coefficient	Solvent content
2.52	51.28

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 110.441	α = 90
b = 99.273	β = 105.33
c = 86.245	γ = 90

Symmetry
Space Group	C 1 2 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	ADSC QUANTUM 4		2006-12-19	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	APS BEAMLINE 24-ID-C	0.9792	APS	24-ID-C

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Merge 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	2.3	40	98.7	0.084	12	4	39615	39100	-3

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	2.3	2.38	91.2		0.422		3.5	3598

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Starting model	Resolution (High)	Resolution (Low)	Number Reflections (All)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	1. EfaLigA (aa 71-317 from PDB 1TA8) 2. TfiLigA (aa 433-584 and 321-391 from PDB 1V9P)	2.3	30.34	39734	39098	1959	98.4	0.217	0.254	RANDOM	39.4

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]
-2.82		4.85	-0.38		3.2

RMS Deviations
Key	Refinement Restraint Deviation
c_dihedral_angle_d	21.4
c_scangle_it	3.06
c_mcangle_it	2.18
c_scbond_it	2.05
c_mcbond_it	1.34
c_angle_deg	1.2
c_improper_angle_d	1.01
c_bond_d	0.006

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	4565
Nucleic Acid Atoms	1062
Solvent Atoms	320
Heterogen Atoms	44

Software

Software
Software Name	Purpose
DENZO	data reduction
SCALEPACK	data scaling
CNS	refinement
PDB_EXTRACT	data extraction
ADSC	data collection
MOLREP	phasing

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM157729.