Publication Date:
2001-09-08
Description:
Multidrug resistance (MDR) is a serious medical problem and presents a major challenge to the treatment of disease and the development of novel therapeutics. ABC transporters that are associated with multidrug resistance (MDR-ABC transporters) translocate hydrophobic drugs and lipids from the inner to the outer leaflet of the cell membrane. To better elucidate the structural basis for the "flip-flop" mechanism of substrate movement across the lipid bilayer, we have determined the structure of the lipid flippase MsbA from Escherichia coli by x-ray crystallography to a resolution of 4.5 angstroms. MsbA is organized as a homodimer with each subunit containing six transmembrane alpha-helices and a nucleotide-binding domain. The asymmetric distribution of charged residues lining a central chamber suggests a general mechanism for the translocation of substrate by MsbA and other MDR-ABC transporters. The structure of MsbA can serve as a model for the MDR-ABC transporters that confer multidrug resistance to cancer cells and infectious microorganisms.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chang, G -- Roth, C B -- GM61905-01/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2001 Sep 7;293(5536):1793-800.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Biology, MB-9, The Scripps Research Institute, La Jolla, CA 92037, USA. gchang@scripps.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11546864" target="_blank"〉PubMed〈/a〉
Keywords:
*ATP-Binding Cassette Transporters
;
Adenosine Triphosphate/metabolism
;
Amino Acid Sequence
;
Bacterial Proteins/*chemistry/genetics/metabolism
;
Binding Sites
;
Biological Transport
;
Crystallography, X-Ray
;
Dimerization
;
*Drug Resistance, Microbial
;
*Drug Resistance, Multiple
;
Escherichia coli/*enzymology
;
Lipid A/metabolism
;
Membrane Proteins/*chemistry/genetics/metabolism
;
Models, Molecular
;
Molecular Sequence Data
;
Protein Structure, Secondary
;
Protein Structure, Tertiary
;
Sequence Alignment
;
Static Electricity
;
Structure-Activity Relationship
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
