Functionally important ATP binding and hydrolysis sites in Escherichia coli MsbA. Biochemistry 2008 Dec 30;47(52):13878-86
Date
12/05/2008Pubmed ID
19053284Pubmed Central ID
PMC2637178DOI
10.1021/bi801745uScopus ID
2-s2.0-58849132410 (requires institutional sign-in at Scopus site) 27 CitationsAbstract
ATP-binding cassette (ABC) transporters make up one of the largest classes of proteins found in nature, and their ability to move a variety of substrates across the membrane using energy from the binding or hydrolysis of ATP is essential to an array of human pathologies and to bacterial viability. MsbA is an essential ABC transporter that specifically transports lipid A across the inner membranes of Gram-negative organisms such as Escherichia coli. The exact mechanisms of function during the binding and hydrolysis of ATP at the molecular level remain unclear. The studies presented and summarized in this work directly address the role and local dynamics of specific residues within the conserved ABC motifs in E. coli MsbA using in vivo growth and biochemical activity assays coupled with site-directed spin labeling electron paramagnetic resonance (EPR) spectroscopy motional and accessibility analysis. This first comprehensive analysis of the specific residues in these motifs within MsbA indicates that closure of the dimer interface does not occur upon ATP binding in this transporter.
Author List
Westfahl KM, Merten JA, Buchaklian AH, Klug CSAuthor
Candice S. Klug PhD Professor in the Biophysics department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
ATP-Binding Cassette TransportersAdenosine Triphosphate
Amino Acid Motifs
Bacterial Proteins
Binding Sites
Conserved Sequence
Dimerization
Electron Spin Resonance Spectroscopy
Escherichia coli Proteins
Hydrolysis
Lipid A