Preliminary structural characterization of human SOUL, a haem-binding protein

The authors acknowledge financial support from Fundacao para a Ciencia e Tecnologia, Portugal through grant SFRH/BPD/30239/2006 and project PTDC/QUI/64203/2006. The authors also acknowledge the ESRF, Grenoble (beamlines ID14- EH2, ID14- EH4, ID23- EH1 and ID-29) for access and technical support during data collection. Human SOUL (hSOUL) is a 23 kDa haem-binding protein that was first identified as the PP23 protein isolated from human full-term placentas. Here, the overexpression, purification and crystallization of hSOUL are reported. The crystals belonged to space group P6422, with unit-cell parameters a = b = 145, c = 60 Å and one protein molecule in the asymmetric unit. X-ray diffraction data were collected to 3.5 Å resolution at the ESRF. A preliminary model of the three-dimensional structure of hSOUL was obtained by molecular replacement using the structures of murine p22HBP (PDB codes 2gov and 2hva), obtained by solution NMR, as search models. publishersversion published