Chains and heterogens:
PDB Chain Sequences:
>1i74A (A:) skilvfghqnpdsdaigssmayaylkrqlgvdaqavalgnpneetafvldyfgiqappvv ksaqaegakqviltdhnefqqsiadirevevvevvdhhrvanfetanplymrlepvgsas sivyrlykengvaipkeiagvmlsglisdtlllksptthasdpavaedlakiagvdlqey glamlkagtnlasktaaqlvdidaktfelngsqvrvaqvntvdinevlerqneieeaika sqaangysdfvlmitdilnsnseilalgnntdkveaafnftlknnhaflagavsrkkqvv pqltesfng
>1i74B (B:) skilvfghqnpdsdaigssmayaylkrqlgvdaqavalgnpneetafvldyfgiqappvv ksaqaegakqviltdhnefqqsiadirevevvevvdhhrvanfetanplymrlepvgsas sivyrlykengvaipkeiagvmlsglisdtlllksptthasdpavaedlakiagvdlqey glamlkagtnlasktaaqlvdidaktfelngsqvrvaqvntvdinevlerqneieeaika sqaangysdfvlmitdilnsnseilalgnntdkveaafnftlknnhaflagavsrkkqvv pqltesfng