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From Constructs to Crystals – Towards Structure Determination of β-barrel Outer Membrane Proteins
Published on: July 4, 2016
Crystallization and preliminary X-ray diffraction analysis of the haem-binding protein HemS from Yersinia
Sabine Schneider1, Massimo Paoli
1Centre for Biomolecular Sciences, School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, England.
Bacteria have evolved strategies to acquire iron from their environment. Pathogenic microbes rely on specialized proteins to ;steal' haem from their host and use it as an iron source. HemS is the ultimate recipient of a molecular-relay system for haem uptake in Gram-negative species, functioning as the cytosolic carrier of haem. Soluble expression and high-quality diffraction crystals were obtained for HemS from Yersinia enterocolitica. Crystals belong to the orthorhombic space group I222, with unit-cell parameters a = 74.86, b = 77.45, c = 114.09 A, and diffract X-rays to 2.6 A spacing in-house. Determination of the structure of the haem-HemS complex will reveal the molecular basis of haem binding.
Bacteria have evolved strategies to acquire iron from their environment. Pathogenic microbes rely on specialized proteins to ;steal' haem from their host and use it as an iron source. HemS is the ultimate recipient of a molecular-relay system for haem uptake in Gram-negative species, functioning as the cytosolic carrier of haem. Soluble expression and high-quality diffraction crystals were obtained for HemS from Yersinia enterocolitica. Crystals belong to the orthorhombic space group I222, with unit-cell parameters a = 74.86, b = 77.45, c = 114.09 A, and diffract X-rays to 2.6 A spacing in-house. Determination of the structure of the haem-HemS complex will reveal the molecular basis of haem binding.

