Chains and heterogens:
PDB Chain Sequences:
>1iw6A (A:) tgrpewiwlalgtalmglgtlyflvkgmgvsdpdakkfyaittlvpaiaftmylsmllgy gltmvpfggeqnpiywaryadwlfttplllldlallvdadqgtilalvgadgimigtglv galtkvysyrfvwwaistaamlyilyvlffgftskaesmrpevastfkvlrnvtvvlwsa ypvvwligsegagivplnietllfmvldvsakvgfglillrsraifg