Experiment: 1KMK

E. coli NifS/CsdB protein at 2.20A with the cysteine perselenide intermediate (residue CSZ).

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	1JF9

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	7	291	4M NACL, pH 7, VAPOR DIFFUSION, HANGING DROP, temperature 291K

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 125.855	α = 90
b = 125.855	β = 90
c = 133.2	γ = 90

Symmetry
Space Group	P 43 21 2

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		2001-10-01	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	NSLS BEAMLINE X4A	0.9790	NSLS	X4A

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	2.2	20	87.9	0.055	7.2		49125	49125

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	2.2	2.28	67.3		0.4	2.1

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 (Depositor)	R-Work (DCC)	R-Free (Depositor)	R-Free (DCC)	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	starting model 1jf9	Rfree test	1jf9	2.2	20	48896	48896	2450	87.9	0.196	0.186	0.239	0.2148	5% random selection

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
p_angle_deg	1.9
p_bond_d	0.015

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	3120
Nucleic Acid Atoms
Solvent Atoms	485
Heterogen Atoms	21

Software

Software
Software Name	Purpose
DENZO	data reduction
SCALEPACK	data scaling
REFMAC	refinement