LCP crystallization and X-ray diffraction analysis of VcmN, a MATE transporter fromVibrio cholerae
Multidrug and toxic compound extrusion (MATE) transporters, one of the multidrug exporter families, efflux xenobiotics towards the extracellular side of the membrane. Since MATE transporters expressed in bacterial pathogens contribute to multidrug resistance, they are important therapeutic targets. Here, a MATE-transporter homologue fromVibrio cholerae, VcmN, was overexpressed inEscherichia coli, purified and crystallized in lipidic cubic phase (LCP). X-ray diffraction data were collected to 2.5 Å resolution from a single crystal obtained in a sandwich plate. The crystal belonged to space groupP212121, with unit-cell parametersa= 52.3,b= 93.7,c= 100.2 Å. As a result of further LCP crystallization trials, crystals of larger size were obtained using sitting-drop plates. X-ray diffraction data were collected to 2.2 Å resolution from a single crystal obtained in a sitting-drop plate. The crystal belonged to space groupP212121, with unit-cell parametersa= 61.9,b= 91.8,c= 100.9 Å. The present work provides valuable insights into the atomic resolution structure determination of membrane transporters.