3F87 UNKNOWN FUNCTION, ALPHA/BETA-PEPTIDE, HELIX BUNDLE, FOLDAMER, COILED COIL, GCN4 DERIVATIVE AN ALPHA/BETA-PEPTIDE HELIX BUNDLE WITH A PURE BETA-AMINO ACID CORE AND A DISTINCTIVE QUARTERNARY STRUCTURE: GCN4PLI DERIVATIVE WITH BETA RESIDUES AT A AND D HEPTAD POSITIONS - HIGHER SYMMETRY CRYSTAL