Chains and heterogens:
PDB Chain Sequences:
>1ssxA (A:) anivggieysinnaslcsvgfsvtrgatkgfvtaghcgtvnatariggavvgtfaarvfp gndrawvsltsaqtllprvangssfvtvrgsteaavgaavcrsgrttgyqcgtitaknvt anyaegavrgltqgnacmgrgdsggswitsagqaqgvmsggnvqsngnncgipasqrssl ferlqpilsqyglslvtg