The bacterial amino-acid transporter MhsT from the SLC6A family has been crystallized in complex with different substrates in order to understand the determinants of the substrate specificity of the transporter. Surprisingly, crystals of the different MhsT-substrate complexes showed interrelated but different crystal-packing arrangements. Space-group assignment and structure determination of these different crystal forms present challenging combinations of pseudosymmetry, twinning and translational noncrystallographic symmetry.
Keywords: MhsT; X-ray crystallography; bacterial amino-acid transporters; membrane proteins; pseudomerohedral twinning; pseudosymmetry; translational NCS; translational symmetry.
open access.