>1xn1B (B:) observed residues (from ATOM records)
sfkiafiqarwhadivdearksfvaelaaktggsveveifdvpgayeiplhaktlartgr
yaaivgaafvidggiyrhdfvatavingmmqvqletevpvlsvvltphhfheskehhdff
hahfkvkgveaahaalqivsersriaa