Document Detail

Transforming a drug/H+ antiporter into a polyamine importer by a single mutation.
MedLine Citation:
PMID:  23035252     Owner:  NLM     Status:  MEDLINE    
EmrE, a multidrug antiporter from Escherichia coli, has presented biochemists with unusual surprises. Here we describe the transformation of EmrE, a drug/H(+) antiporter to a polyamine importer by a single mutation. Antibiotic resistance in microorganisms may arise by mutations at certain chromosomal loci. To investigate this phenomenon, we used directed evolution of EmrE to assess the rate of development of novel specificities in existing multidrug transporters. Strikingly, when a library of random mutants of EmrE was screened for resistance to two major antibacterial drugs--norfloxacin, a fluoroquinolone, and erythromycin, a macrolide--proteins with single mutations were found capable of conferring resistance. The mutation conferring erythromycin resistance resulted from substitution of a fully conserved and essential tryptophan residue to glycine, and, as expected, this protein lost its ability to recognize and transport the classical EmrE substrates. However, this protein functions now as an electrochemical potential driven importer of a new set of substrates: aliphatic polyamines. This mutant provides a unique paradigm to understand the function and evolution of distinct modes of transport.
Shlomo Brill; Ofir Sade Falk; Shimon Schuldiner
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2012-10-03
Journal Detail:
Title:  Proceedings of the National Academy of Sciences of the United States of America     Volume:  109     ISSN:  1091-6490     ISO Abbreviation:  Proc. Natl. Acad. Sci. U.S.A.     Publication Date:  2012 Oct 
Date Detail:
Created Date:  2012-10-17     Completed Date:  2012-12-31     Revised Date:  2013-07-11    
Medline Journal Info:
Nlm Unique ID:  7505876     Medline TA:  Proc Natl Acad Sci U S A     Country:  United States    
Other Details:
Languages:  eng     Pagination:  16894-9     Citation Subset:  IM    
Department of Biological Chemistry, Alexander A. Silberman Institute of Life Sciences, Hebrew University of Jerusalem, 91904 Jerusalem, Israel.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Antiporters / genetics*,  metabolism*
Carbon Radioisotopes / metabolism
Directed Molecular Evolution
Drug Resistance, Multiple, Bacterial / genetics*
Escherichia coli / genetics*
Escherichia coli Proteins / genetics*,  metabolism*
Mutation / genetics*
Plasmids / genetics
Polyamines / metabolism*
Proteolipids / metabolism
Putrescine / metabolism
Grant Support
Reg. No./Substance:
0/Antiporters; 0/Carbon Radioisotopes; 0/Escherichia coli Proteins; 0/Polyamines; 0/Proteolipids; 0/proteoliposomes; 110-60-1/Putrescine; 114-07-8/Erythromycin; 147995-06-0/EmrE protein, E coli; 70458-96-7/Norfloxacin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Structural basis for promiscuity and specificity during Candida glabrata invasion of host epithelia.
Next Document:  Comprehensive analysis of surface charged residues involved in thermal stability in Alicyclobacillus...