4FT8

E. coli Catabolite Activator Protein with Cobalt and Sulfate Ligands

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	SYNCHROTRON
Source details	NSLS BEAMLINE X8C
Synchrotron site	NSLS
Beamline	X8C
Temperature [K]	108
Detector technology	CCD
Collection date	2007-11-16
Detector	ADSC QUANTUM 4
Wavelength(s)	1.07
Spacegroup name	P 21 21 2
Unit cell lengths	104.143, 108.452, 44.320
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	40.781 - 1.966
R-factor	0.1977
Rwork	0.196
R-free	0.23000
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	search 1: 1ZRC CAP N-terminal domain dimer; searches 2 3: 1ZRC CAP individual C-terminal domain
RMSD bond length	0.005
RMSD bond angle	1.000
Data reduction software	DENZO
Data scaling software	SCALEPACK
Phasing software	PHASER
Refinement software	PHENIX

Data quality characteristics

	Overall	Inner shell	Outer shell
Low resolution limit [Å]	50.000	50.000	2.030
High resolution limit [Å]	1.960	4.220	1.960
Rmerge	0.088	0.041	0.778
Number of reflections	35645
<I/σ(I)>	9.5
Completeness [%]	97.1	98.5	90.5
Redundancy	5.1	4.9	4.2

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION, HANGING DROP	6.5	293	A CAP-DNA complex was screened by hanging-drop vapor diffusion with Hampton Research Crystal Screens and pregreased VDX plates. Optimization of Crystal Screen 2 condition #25 yielded ruby-red colored crystals appearing within 3 days at 20 C in 0.01 M CoCl2.6H2O, 0.1 M MES monohydrate pH 6.5 and 2.5 M (NH4)2SO4. The crystallization process yielded crystals containing only CAP protein without DNA, VAPOR DIFFUSION, HANGING DROP, temperature 293K