Chains and heterogens:
PDB Chain Sequences:
>1f5kU (U:) iiggefttienqpwfaaiyrrhrggsvtyvcggslispcwvisathcfidypkkedyivy lgrsrlnsntqgemkfevenlilhkdysadtlahhndiallkirskegrcaqpsrtiqti slpsmyndpqfgtsceitgfgkenstdylypeqlkmtvvklishrecqqphyygsevttk mlcaadpqwktdscqgdsggplvcslqgrmtltgivswgrgcalkdkpgvytrvshflpw irshtke