Chains and heterogens:
PDB Chain Sequences:
>1s3gA (A:) mnivlmglpgagkgtqadrivekygtphistgdmfraaiqegtelgvkaksfmdqgalvp devtigivrerlsksdcdngflldgfprtvpqaealdqlladmgrkiehvlniqvekeel iarltgrrickvcgtsyhllfnppqvegkcdkdggelyqraddnpdtvtnrlevnmnqta pllafydskevlvningqkdikdvfkdldvilqgngq