Preliminary X-ray crystallographic analysis of a Ca²⁺-binding protein human S100A1

S100A1, a Ca²⁺-binding protein from the S100 protein family, has been crystallized by the vapour-diffusion method using polyethylene glycol 4000 as the precipitant at pH 8.5. The crystal belongs to space group P6₃. The unit-cell parameters are a = b = 57.3, c = 104.7 Å. There appear to be two S100A1 molecules in the asymmetric unit. The crystals were stable during exposure to X-rays and diffract to 2.6 Å resolution in-house.