Acta Crystallographica Section D

Biological Crystallography

Volume 58, Part 9 (September 2002)

crystallization papers

Acta Cryst. (2002). D58, 1504-1506 [ doi:10.1107/S0907444902011794 ]

Cloning, purification, crystallization and preliminary X-ray analysis of DOS heme domain, a new heme oxygen sensor in Escherichia coli

H. Park, C. Suquet, M. I. Savenkova, J. D. Satterlee and C. Kang

Abstract: The heme-containing PAS domain of the direct oxygen-sensor protein (DOS_H), a bona fide oxygen-sensor protein, has been cloned from Escherichia coli strain K12 and successfully purified. The oxidized form of this protein was crystallized by the hanging-drop method with a PEG 8000-based precipitant. Preliminary X-ray diffraction studies of the PAS-domain crystal show that it belongs to the orthorhombic space group P2₁2₁2₁, with unit-cell parameters a = 46.1, b = 68.1, c = 82.6 Å. A complete diffraction data set was collected to 1.9 Å for MAD phasing. The electron-density map shows two molecules in an asymmetric unit and a unique six-coordination of the heme iron.

Keywords: oxygen-sensor proteins; PAS domains; heme domains.