Chains and heterogens:
PDB Chain Sequences:
>1ck3A (A:) hpetlvkvkdaedqlgarvgyieldlnsgkilesfrpeerfpmmstfkvllcgavlsrid agqeqlgrrihysqndlveyspvtekhltdgmtvrelcsaaitmsdntaanlllttiggp keltaflhnmgdhvtrldrwepelneaipnderdttmpvamattlrklltgelltlasrq qlidwmeadkvagpllrsalpagwfiadksgagergsrgiiaalgpdgkpsrivviyttg sqatmderdrqiaeigaslikhw