Crystallization and preliminary X-ray diffraction analysis of the cytosolic domain of the Mg²⁺ transporter MgtE

The MgtE family of Mg²⁺ transporters is ubiquitously conserved in all domains of life. The cytosolic domains of the MgtE Mg²⁺ transporters include a cystathionine-β-synthase (CBS) domain which is known to play a regulatory function in transporter proteins. The cytosolic domain of MgtE from Thermus thermophilus was overexpressed, purified and crystallized in the presence and absence of Mg²⁺. The crystals formed in the presence of Mg²⁺ diffracted X-rays to 2.3 Å resolution using synchrotron radiation, belong to space group P6₅22 with unit-cell parameters a = b = 57.7, c = 317.6 Å and are expected to contain one molecule in the asymmetric unit. The crystals formed in the absence of Mg²⁺ diffracted X-rays to 3.5 Å resolution using synchrotron radiation, belong to space group P2₁2₁2₁ with unit-cell parameters a = 77.0, b = 100.3, c = 100.3 Å and are expected to contain two molecules in the asymmetric unit.