6NCS

Crystal structure of N-acetylneuraminic acid (Sialic acid) synthetase from Leptospira borgpetersenii serovar Hardjo-bovis in complex with citrate

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, SITTING DROP	7.5	285	Molecular Dimensions Morpheus screen, condition G8: 12.5% w/v PEG 1000, 12.5% w/v PEG 3350, 12.5% v/v MPD: 20mM each: sodium formate, ammonium acetate, trisodium citrate, sodium potassium L-tartrate, sodium oxamate: 100mM MOPS/HEPES-Na pH 7.5: LpboA.19655.b.B1.PS38488 at 22.9mg/ml. For phasing, the crystal was incubated for 20sec in reservoir solution with additional 10% of 5M NaI in ethylene glycol (500mM final concentration). Cryo: direct: tray: 303852g8: puck hyz8-5.

Crystal Properties
Matthews coefficient	Solvent content
2.19	43.8

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 69.88	α = 90
b = 49.12	β = 112.41
c = 88.85	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	RIGAKU SATURN 944+	RIGAKU VARIMAX	2017-11-10	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	ROTATING ANODE	RIGAKU FR-E+ SUPERBRIGHT	1.5418

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Merge I (Observed)	Rrim I (All)	CC (Half)	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	43.375	97.1	0.057	0.06	0.999	25	10.241		50583			26.797

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	Rrim I (All)	CC (Half)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	1.8	1.85	88.2		0.398	0.428	0.941	4.23	6.728

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	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	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	SAD	THROUGHOUT	1.8	43.375	1.35	50574	2017	97.19	0.1573	0.1556	0.1983	0	24.9485

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
f_dihedral_angle_d	13.204
f_angle_d	0.824
f_chiral_restr	0.056
f_bond_d	0.006
f_plane_restr	0.005

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	4337
Nucleic Acid Atoms
Solvent Atoms	524
Heterogen Atoms	68

Software

Software
Software Name	Purpose
XDS	data reduction
XSCALE	data scaling
PHENIX	refinement
PDB_EXTRACT	data extraction
PHASER	phasing
PARROT	phasing
ARP/wARP	model building
Coot	model building

RCSB PDB Core Operations are funded by the National Science Foundation (DBI-1832184), 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 R01GM133198.