>1xn1A (A:) observed residues (from ATOM records) tsfkiafiqarwhadivdearksfvaelaaktggsveveifdvpgayeiplhaktlartg ryaaivgaafvidggiyrhdfvatavingmmqvqletevpvlsvvltphhfheskehhdf fhahfkvkgveaahaalqivsersriaa