>4tw1B (B:) observed residues (from ATOM records)
tapddigkngkitkrtetvydektnilqnlqfdfiddptydknvllvkkqgsihsnlkfe
shkeeknsnwlkypseyhvdfqvkrnrkteildqlpknkistakvdstfsyssggkgrts
snsysktisynqqnydtiasgknnnwhvhwsviandlkyggevknrndellfyrntriat
venpelsfaskyrypalvrsgfnpefltylsneksnektqfevtytrnqdilknrpgihy
appileknkdgqrlivtyevdwknktvkvvdkysddnkpyke