Use of a new label, (13)==(18)O, in the determination of a structural model of phospholamban in a lipid bilayer. Spatial restraints resolve the ambiguity arising from interpretations of mutagenesis data.
A structural model of pentameric phospholamban (Plb) in a lipid bilayer has been derived using a combination of experimental data, obtained from ATR-FTIR site-directed dichroism, and the implementation of the resulting restraints during a molecular dynamics simulation. Plb (residues 24-52) has been synthesised incorporating a new label, 1-(13)C==(18)O, at residues 42 and 43. We have not only determined the tilt of the helices, 10(+/-6) degrees, but also the relative orientation of the transmembrane segments, with an omega angle of -32(+/-10) degrees for L42. This angle is taken as zero in the direction of the helix tilt. Plb is a simple test case where site-directed dichroism has been applied to resolve the indeterminacy arising from the mutagenesis data available. The results presented point specifically to a single structural model for Plb.
Torres
J
J
Cambridge Centre for Molecular Recognition Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK.
Adams
P D
PD
Arkin
I T
IT
D000577:Amides / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002247:Carbon Isotopes; D003198:Computer Simulation; D008051:Lipid Bilayers / Q000378:metabolism*; D008958:Models, Molecular; D016296:Mutagenesis / Q000235:genetics*; D010103:Oxygen Isotopes; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017433:Protein Structure, Secondary; D017550:Spectroscopy, Fourier Transform Infrared; D014732:Vibration; D000099211:Phospholamban
D000577:Amides; D002135:Calcium-Binding Proteins; D002247:Carbon Isotopes; D008051:Lipid Bilayers; D010103:Oxygen Isotopes; D010446:Peptide Fragments; D000099211:Phospholamban