Crystallization and preliminary structural analysis of the Listeria monocytogenes Ca²⁺-ATPase LMCA1

Ca²⁺-ATPases are ATP-driven membrane pumps that are responsible for the transport of Ca²⁺ ions across the membrane. The Listeria monocytogenes Ca²⁺-ATPase LMCA1 has been crystallized in the Ca²⁺-free state stabilized by AlF₄^-, representing an occluded E2-P_i-like state. The crystals belonged to space group P2₁2₁2 and a complete data set extending to 4.3 Å resolution was collected. A molecular-replacement solution was obtained, revealing type I packing of the molecules in the crystal. Unbiased electron-density features were observed for AlF₄^- and for shifts of the helices, which were indicative of a reliable structure determination.