>4m21B (B:) observed residues (from ATOM records)
mteyklvvvgacgvgksaltiqliqnhfvdsyrkqvvidgetslldildtaysamrdqym
rtgegfllvfainntksfedihhyreqikrvkdsedvpmvlvgnksdlpsrtvdtkqaqd
larsygipfietsaktrqgvddafytlvreirkhke