>1xbtD (D:) observed residues (from ATOM records)
rgqiqvilgpmfsgkstelmrrvrrfqiaqykclvikyakdtrysalpacllrdvaqeal
gvavigidegqffpdivefceamanagktvivaaldgtfqrkpfgailnlvplaesvvkl
tavcmecfreaaytkrlgtekeveviggadkyhsvcrlcyfk