>1extA (A:) observed residues (from ATOM records)
svcpqgkyihpqnnsicctkchkgtylyndcpgpgqdtdcrecesgsftasenhlrhcls
cskcrkemgqveissctvdrdtvcgcrknqyrhywsenlfqcfncslclngtvhlscqek
qntvctchagfflrenecvscsnckkslectklclpqien