High-resolution conformation of gramicidin A in a lipid bilayer by solid-state NMR.
Solid-state nuclear magnetic resonance spectroscopy of uniformly aligned preparations of gramicidin A in lipid bilayers has been used to elucidate a high-resolution dimeric structure of the cation channel conformation solely on the basis of the amino acid sequence and 144 orientational constraints. This initial structure defines the helical pitch as single-stranded, fixes the number of residues per turn at six to seven, specifies the helix sense as right-handed, and identifies the hydrogen bonds. Refinement of this initial structure yields reasonable hydrogen-bonding distances with only minimal changes in the torsion angles.
Ketchem
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RR
Institute of Molecular Biophysics, Florida State University, Tallahassee 32306.
Hu
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Cross
T A
TA
D000595:Amino Acid Sequence; D006096:Gramicidin / Q000737:chemistry*; D006860:Hydrogen Bonding; D008051:Lipid Bilayers / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary
D008051:Lipid Bilayers; D006096:Gramicidin