2f1m
From Proteopedia
Conformational flexibility in the multidrug efflux system protein AcrA
Structural highlights
FunctionACRA_ECOLI AcrA-AcrB-AcrZ-TolC is a drug efflux protein complex with broad substrate specificity that uses the proton motive force to export substrates. This subunit may act as an adapter protein that links AcrB and TolC stably together. It is elongated in shape, being long enough to span the periplasm.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedIntrinsic resistance to multiple drugs in many gram-negative bacterial pathogens is conferred by resistance nodulation cell division efflux pumps, which are composed of three essential components as typified by the extensively characterized Escherichia coli AcrA-AcrB-TolC system. The inner membrane drug:proton antiporter AcrB and the outer membrane channel TolC export chemically diverse compounds out of the bacterial cell, and require the activity of the third component, the periplasmic protein AcrA. The crystal structures of AcrB and TolC have previously been determined, and we complete the molecular picture of the efflux system by presenting the structure of a stable fragment of AcrA. The AcrA fragment resembles the elongated sickle shape of its homolog Pseudomonas aeruginosa MexA, being composed of three domains: beta-barrel, lipoyl, and alpha-helical hairpin. Notably, unsuspected conformational flexibility in the alpha-helical hairpin domain of AcrA is observed, which has potential mechanistic significance in coupling between AcrA conformations and TolC channel opening. Conformational flexibility in the multidrug efflux system protein AcrA.,Mikolosko J, Bobyk K, Zgurskaya HI, Ghosh P Structure. 2006 Mar;14(3):577-87. PMID:16531241[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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