Chains and heterogens:
PDB Chain Sequences:
>1xx4A (A:) fsnkrvlvekegeagiavmkfknppvnslslefltefvisleklendksirgviltserp gifsagldlmemygrnpahyaeywkavqelwlrlylsnltlisaingaspaggclmaltc dyrimadnskytiglnesllgivapfwlkdnyvntighraaeralqlgtlfppaealkvg lvdevvpedqvhskarsvmakwftipdhsrqltksmmrkatadnlikqreadiqnftsfi srdsiqkslhvyleklkqkkg
>1xx4A (A:) fsnkrvlvekagiavmkfknppvnslslefltefvisleklendksirgviltserpgif sagldlmemygrnpahyaeywkavqelwlrlylsnltlisaingaspaggclmaltcdyr imadnskytiglnesllgivapfwlkdnyvntighraaeralqlgtlfppaealkvglvd evvpedqvhskarsvmakwftipdhsrqltksmmrkatadnlikqreadiqnftsfisrd siqkslhvyleklk