6gv1
From Proteopedia
Crystal structure of E.coli Multidrug/H+ antiporter MdfA in outward open conformation with bound Fab fragment
Structural highlights
Function[MDFA_ECOLI] Efflux pump driven by the proton motive force. Confers resistance to a broad spectrum of chemically unrelated drugs. Confers resistance to a diverse group of cationic or zwitterionic lipophilic compounds such as ethidium bromide, tetraphenylphosphonium, rhodamine, daunomycin, benzalkonium, rifampicin, tetracycline, puromycin, and to chemically unrelated, clinically important antibiotics such as chloramphenicol, erythromycin, and certain aminoglycosides and fluoroquinolones. Overexpression results in isopropyl-beta-D-thiogalactopyranoside (IPTG) exclusion and spectinomycin sensitivity. Transport of neutral substrates is electrogenic, whereas transport of cationic substrates is electroneutral. In addition to its role in multidrug resistance, confers extreme alkaline pH resistance, allowing the growth under conditions that are close to those used normally by alkaliphiles. This activity requires Na(+) or K(+).[1] [2] [3] [4] [5] Publication Abstract from PubMedThe active efflux of antibiotics by multidrug-resistance (MDR) transporters is a major pathway of drug resistance and complicates the clinical treatment of bacterial infections. MdfA is a member of the major facilitator superfamily (MFS) from Escherichia coli and provides resistance to a wide variety of dissimilar toxic compounds, including neutral, cationic and zwitterionic substances. The 12-transmembrane-helix MdfA was expressed as a GFP-octahistidine fusion protein with a TEV protease cleavage site. Following tag removal, MdfA was purified using two chromatographic steps, complexed with a Fab fragment and further purified using size-exclusion chromatography. MdfA and MdfA-Fab complexes were subjected to both vapour-diffusion and lipidic cubic phase (LCP) crystallization techniques. Vapour-diffusion-grown crystals were of type II, with poor diffraction behaviour and weak crystal contacts. LCP lipid screening resulted in type I crystals that diffracted to 3.4 A resolution and belonged to the hexagonal space group P6122. The multidrug-resistance transporter MdfA from Escherichia coli: crystallization and X-ray diffraction analysis.,Nagarathinam K, Jaenecke F, Nakada-Nakura Y, Hotta Y, Liu K, Iwata S, Stubbs MT, Nomura N, Tanabe M Acta Crystallogr F Struct Biol Commun. 2017 Jul 1;73(Pt 7):423-430. doi:, 10.1107/S2053230X17008500. Epub 2017 Jun 20. PMID:28695852[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||
