Chains and heterogens:
PDB Chain Sequences:
>1fsyA (A:) apqqindivhrtitplieqqkipgmavaviyqgkpyyftwgyadiakkqpvtqqtlfelg svsktftgvlggdaiargeiklsdpttkywpeltakqwngitllhlatytagglplqvpd evksssdllrfyqnwqpawapgtqrlyanssiglfgalavkpsglsfeqamqtrvfqplk lnhtwinvppaeeknyawgyregkavhvspgaldaeaygvkstiedmarwvqsnlkpldi nektlqqgiqlaqsrywqtgdmyqglgwemldwpvnpdsiingsdnkialaarpvkaitp ptpavraswvhktgatggfgsyvafipekelgivmlanknypnparvdaawqilnala
>1fsyB (B:) apqqindivhrtitplieqqkipgmavaviyqgkpyyftwgyadiakkqpvtqqtlfelg svsktftgvlggdaiargeiklsdpttkywpeltakqwngitllhlatytagglplqvpd evksssdllrfyqnwqpawapgtqrlyanssiglfgalavkpsglsfeqamqtrvfqplk lnhtwinvppaeeknyawgyregkavhvspgaldaeaygvkstiedmarwvqsnlkpldi nektlqqgiqlaqsrywqtgdmyqglgwemldwpvnpdsiingsdnkialaarpvkaitp ptpavraswvhktgatggfgsyvafipekelgivmlanknypnparvdaawqilnala