Chains and heterogens:
PDB Chain Sequences:
>1em2A (A:) sfsaqereyirqgkeatavvdqilaqeenwkfeknneygdtvytievpfhgktfilktfl pcpaelvyqevilqpermvlwnktvtacqilqrvedntlisydvsagaaggvvsprdfvn vrrierrrdrylssgiatshsakppthkyvrgengpggmivlksasnprvctfvwilntd lkgrlprylihqslaatmfefafhlrqriselga