Chains and heterogens:
PDB Chain Sequences:
>1f3aA (A:) agkpvlhyfnargrmecirwllaaagvefeekfiqspedleklkkdgnlmfdqvpmveid gmklaqtrailnyiatkydlygkdmkeralidmysegildltemigqlvlcppdqreakt alakdrtknrylpafekvlkshgqdylvgnrltrvdihllevllyveefdaslltpfpll kafksrisslpnvkkflqpgsqrkppmdakqiqearkafki
>1f3aB (B:) agkpvlhyfnargrmecirwllaaagvefeekfiqspedleklkkdgnlmfdqvpmveid gmklaqtrailnyiatkydlygkdmkeralidmysegildltemigqlvlcppdqreakt alakdrtknrylpafekvlkshgqdylvgnrltrvdihllevllyveefdaslltpfpll kafksrisslpnvkkflqpgsqrkppmdakqiqearkafki