8GEP

SULFITE REDUCTASE HEMOPROTEIN NITRATE COMPLEX

Experimental procedure

Temperature [K]	277
Detector technology	IMAGE PLATE
Collection date	1995-10-19
Detector	MARRESEARCH
Spacegroup name	P 21 21 21
Unit cell lengths	69.800, 77.400, 87.800
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	10.000 - 2.200
R-factor	0.189
Rwork	0.189
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	1aop
RMSD bond length	0.011
RMSD bond angle	1.600
Data reduction software	MARXDS
Data scaling software	MARSCALE
Phasing software	X-PLOR (3.1)
Refinement software	X-PLOR (3.1)

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	30.000	2.400
High resolution limit [Å]	2.200	2.200
Rmerge	0.077 *	0.338 *
Number of reflections	22966
<I/σ(I)>	12	2.1
Completeness [%]	92.8	83.5
Redundancy	2.3

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	Vapor diffusion, sitting drop *	7.7		pH 7.7 OXIDIZED CRYSTALS WERE TREATED WITH HYDROXYLAMINE TO FORM THE NITRATE COMPLEX. SIROHEME HAS EITHER FEIII OR FEII AND [4FE-4S] CLUSTER IS +2. THE NITRATE BINDS IN THE ACTIVE SITE BUT DOES NOT COORDINATE THE SIROHEME IRON. THIS IS NAMED HP-NO3 IN THE PRIMARY REFERENCE.

Crystallization Reagents in Literatures

ID	crystal ID	solution	reagent name	concentration (unit)	details
1	1	drop	protein	6 (mg/ml)
2	1	reservoir	potassium phosphate	65 (mM)
3	1	reservoir	EDTA	0.1 (M)
4	1	reservoir	PEGMW8000	15 (%)