>1xbtC (C:) observed residues (from ATOM records)
rgqiqvilgpmfsgkstelmrrvrrfqiaqykclvikyakdtralpacllrdvaqealgv
avigidegqffpdivefceamanagktvivaaldgtfqrkpfgailnlvplaesvvklta
vcmecfreaaytkrlgtekeveviggadkyhsvcrlcyfk