Chains and heterogens:
PDB Chain Sequences:
>3fkvA (A:) apqqindivhrtitplieqqkipgmavaviyqgkpyyftwgyadiakkqpvtqqtlfelg svsrtftgvlggdaiargeiklsdpttkywpeltakqwngitllhlatytagglplqvpd evksssdllrfyqnwqpawapgtqrlyanssiglfgalavkpsglsfeqamqtrvfqplk lnhtwinvppaeeknyawgyregkavhvspgaldaeaygvkstiedmarwvqsnlkpldi nektlqqgiqlaqsrywqtgdmyqglgwemldwpvnpdsiingsdnkialaarpvkaitp ptpavraswvhktgatggfgsyvafipekelgivmlanknypnparvdaawqilnalq
>3fkvA (A:) apqqindivhrtitplieqqkipgmavaviyqgkpyyftwgyadiakkqpvtqqtlfelg svsrtftgvlggdaiargeiklsdpttkywpeltakqwngitllhlatytagglplqvpd evksssdllrfyqnwqpawapgtqrlyanssiglfgalavkpsglsfeqamqtrvfqplk lnhtwinvppaeeknyawgyregkavhvspgaldaeaygvkstiedmarwvqsnlkpldi nektlqqgiqlaqsrywqtgdmyqglgwemldwpvnpdsiingskialaarpvkaitppt pavraswvhktgatggfgsyvafipekelgivmlanknypnparvdaawqilnalq
>3fkvB (B:) apqqindivhrtitplieqqkipgmavaviyqgkpyyftwgyadiakkqpvtqqtlfelg svsrtftgvlggdaiargeiklsdpttkywpeltakqwngitllhlatytagglplqvpd evksssdllrfyqnwqpawapgtqrlyanssiglfgalavkpsglsfeqamqtrvfqplk lnhtwinvppaeeknyawgyregkavhvspgaldaeaygvkstiedmarwvqsnlkpldi nektlqqgiqlaqsrywqtgdmyqglgwemldwpvnpdsiingsdnkialaarpvkaitp ptpavraswvhktgatggfgsyvafipekelgivmlanknypnparvdaawqilnalq